Functions manipulate data and return a result. In addition to an alphabetical listing of all functions, this chapter contains an overview of functions including:
Numeric functions accept numeric input and return numeric values. The numeric functions are:
The character functions that return character values are:
Character functions that return number values are:
TimesTen supports these string functions in SELECT
statements:
A selected value that specifies a string function causes the SELECT
result to be materialized. This causes overhead in both time and space.
The following EMPTY_*
functions initialize LOBs to a non-null value:
The following TO_*
functions convert specific data types into the desired LOB data type.
The NLS character set functions return information about the specified character set.
The general comparison functions perform comparisons between input expressions. The general comparison functions are:
The null-related comparison functions compare expressions against NULL
or return NULL
based on comparison of expressions. The null-related comparison functions are:
Conversion functions convert a value from one data type to another. Some of the conversion function names follow the convention of TO
_datatype
.
The SQL conversion functions are:
For a full description of the datetime data types, see "Datetime data types".
The datetime functions are:
Aggregate functions perform a specific operation over all rows in a group. Aggregate functions return a single result row based on groups of rows, rather than on single rows. They are commonly used with the GROUP BY
clause in a SELECT
statement, where the returned rows are divided into groups. If you omit the GROUP BY
clause, the aggregate functions in the select list are applied to all the rows in the queried table or view.
Aggregate functions can be specified in the select list or the HAVING
clause. See "SELECT" for more information. The value of the expression is computed using each row that satisfies the WHERE
clause.
Many aggregate functions that take a single argument can use the ALL
or DISTINCT
keywords. The default is ALL
. See each aggregate function syntax to see if ALL
or DISTINCT
can be used.
Specify DISTINCT
in an aggregate function to consider only distinct values of the argument expression.
Specify ALL
in an aggregate function to consider all values, including duplicates.
For example, the DISTINCT
average of 1, 1, 1, and 3 is 2. The ALL
average for these results is 1.5.
The ROLLUP
and CUBE
clauses within a GROUP BY
clause produce superaggregate rows where the column values are represented by null values. Because the superaggregate rows are denoted by NULL
, it can be a challenge to differentiate between query results that include a null value and the superaggregate result. In addition, within the returned subtotals, how do you find the exact level of aggregation for a given subtotal? Use the GROUP_ID, GROUPING and GROUPING_ID functions to resolve these issues.
See Chapter 1, "Data Types" for information about the following.
Truncation and type conversion that may occur during the evaluation of aggregate functions.
Precision and scale of aggregate functions involving numeric arguments.
Control of the result type of an aggregate function.
Analytic functions compute an aggregate value based on a group of rows. They differ from aggregate functions in that they return multiple rows for each group. The group of rows is called a window and is defined by the analytic_clause
.
Analytic functions are the last set of operations performed in a query except for the final ORDER BY
clause. All joins, WHERE
, GROUP BY
, and HAVING
clauses are completed before the analytic functions are processed. The final ORDER BY
clause is used to order the result of analytic functions. Analytic functions can appear in the select list of a query or subquery and in the ORDER
BY
clause.
Analytic functions allow you to divide query result sets into groups of rows called partitions. You can define partitions on columns or expressions. You can partition a query result set into just one partition holding all rows, a few large partitions or many small partitions holding just a few rows each.
You can define a sliding window for each row in the partition. This window determines the range of rows used to perform the calculations for the current row. Window sizes are based on a physical number of rows. The window has a starting row and an ending row and the window may move at one or both ends. For example, a window defined for a cumulative sum function would have its starting row fixed at the first row of the partition and the ending rows would slide from the start point to the last row of the partition. In contrast, a window defined for a moving average would have both the start point and end point slide.
You can set the window as large as all the rows in the partition or as small as one row within a partition.
You can specify multiple ordering expressions within each function. This is useful when using functions that rank values because the second expression can resolve ties between identical values for the first expression.
Analytic functions are commonly used to compute cumulative, moving, centered, and reporting aggregates.
Restrictions:
Analytic functions are not supported in global queries or materialized views.
The list of analytic functions follows. Functions followed by an asterisk (*) support the WindowingClause
.
Analytic function syntax:
AnalyticFunctionName ([arguments]) OVER ([AnalyticClause]) AnalyticClause::= QueryPartitionClause [ORDER BY OrderByClause [,...] [WindowingClause]] | ORDER BY OrderByClause [,...] [WindowingClause] QueryPartitionClause::= PARTITION BY { Expression[,Expression]... | (Expression [,Expression]...) } OrderByClause::= Expression [ASC|DESC] [NULLS {FIRST|LAST}] WindowingClause::= ROWS { BETWEEN StartPoint AND EndPoint | StartPoint } StartPoint::= UNBOUNDED PRECEDING | CURRENT ROW | PosNumConstantExpr { PRECEDING | FOLLOWING } EndPoint::= UNBOUNDED FOLLOWING | CURRENT ROW | PosNumConstantExpr { PRECEDING | FOLLOWING }
Parameter | Description |
---|---|
AnalyticFunctionName |
Name of analytic function. |
arguments |
Arguments for the analytic function. Number of arguments depends on the analytic function. Refer to the particular function for specific information on the arguments to the function. |
OVER ( [ AnalyticClause ] ) |
Indicates that the function is an analytic function. This clause is computed after the FROM , WHERE , GROUP BY , and HAVING clauses.
If you do not specify the |
QueryPartitionClause |
Optional clause used in AnalyticClause . Denoted by the PARTITION BY clause. If specified, the query result set is partitioned into groups based on the Expression list. If you omit this clause, then the function treats all rows of the query result set as a single group.
You can specify multiple analytic functions in the same query using either the same or different Valid values for |
ORDER BY OrderByClause |
Optional clause used in AnalyticClause . Use this clause to specify how data is ordered within the partition. Expression cannot be a column alias or position.
You can order the values in a partition on multiple keys each defined by Analytic functions operate in the order specified in this clause. However this clause does not guarantee the order of the result. Use the If you specify the If you do not specify the |
ASC | DESC |
Specifies the ordering sequence (ascending or descending). ASC is the default.
Clause is optional. |
NULLS FIRST | NULLS LAST |
Specifies whether rows that contain NULL values are specified first or last in the ordering sequence. NULLS LAST is the default for ascending order. NULLS FIRST is the default for descending order.
Clause is optional. |
WindowingClause |
Clause is denoted by the ROWS keyword. Specifies for each row a window expressed in physical units (rows). The window is used for calculating the function result. The function is applied to all the rows in the window. The window moves through the query result set or partition from top to bottom.
You cannot specify the The value returned by the analytic function may produce nondeterministic results unless the ordering sequence results in unique ordering. In this case, specify multiple columns in the For the list of functions that allow the |
BETWEEN...AND |
Use the BETWEEN ...AND clause to specify a start point (StartPoint ) and end point (EndPoint ) for the window.
If you omit the |
StartPoint |
Valid values are UNBOUNDED PRECEDING , CURRENT ROW , PosNumConstantExpr PRECEDING or PosNumConstantExpr FOLLOWING .
|
EndPoint |
Valid values are UNBOUNDED FOLLOWING , CURRENT ROW , PosNumConstantExpr PRECEDING or PosNumConstantExpr FOLLOWING .
|
UNBOUNDED PRECEDING |
Use UNBOUNDED PRECEDING to indicate that the window starts at the first row of the partition.
Cannot be used as the end point. |
UNBOUNDED FOLLOWING |
Use UNBOUNDED FOLLOWING to indicate that the window ends at the last row of the partition.
Cannot be used as the start point. |
CURRENT ROW |
As a start point, CURRENT ROW specifies that the window begins at the current row. In this case, the end point cannot be PosNumConstantExpr PRECEDING .
As an end point, |
PosNumConstantExpr {PRECEDING | FOLLOWING } |
If PosNumConstantExpr FOLLOWING is the start point, then the end point must be PosNumConstantExpr FOLLOWING or UNBOUNDED FOLLOWING . If PosNumConstantExpr PRECEDING is the end point, then the start point must be PosNumConstantExpr PRECEDING or UNBOUNDED PRECEDING .
The end point
|
You may want to execute a global query without changing the location of the data. You can use cache grid functions to determine the location of data in a cache grid and then execute a query for the information from that member.
Use these SQL functions in a global query to obtain information about the location of data in the cache grid, which the user can use to map each returned row to a member of the grid.
TTGRIDMEMBERID() - When executed within a global query, gives the member ID in the cache grid of the owning member for each returned row.
TTGRIDNODENAME() - When executed within a global query, returns the name of the node in a cache grid on which the data is located.
TTGRIDUSERASSIGNEDNAME() - Within a global query, returns the user-assigned name of the node in a cache grid on which the data is located.
These functions can be used in a SELECT
statement and in these clauses of a SELECT
statement:
WHERE
clause
GROUP BY
clause
ORDER BY
clause
See "Obtaining information about the location of data in the cache grid" in Oracle TimesTen Application-Tier Database Cache User's Guide for more information.
The ABS
function returns the absolute value of Expression.
ABS
has the parameter:
Parameter | Description |
---|---|
Expression |
Operand or column can be any numeric data type. Absolute value of Expression is returned. |
If Expression
is of type TT_DECIMAL
or NUMBER
, the data type returned is NUMBER
with maximum precision and scale. Otherwise, ABS
returns the same data type as the numeric data type of Expression
.
If the value of Expression
is NULL
, NULL
is returned. If the value of the Expression
is -INF
, INF
is returned.
Create table abstest
and define columns with type BINARY_FLOAT
and TT_INTEGER
. Insert values -BINARY_FLOAT_INFINITY
and -10. Call ABS
to return the absolute value. You see INF
and 10 are the returned values:
Command> CREATE TABLE abstest (col1 BINARY_FLOAT, col2 TT_INTEGER); Command> INSERT INTO abstest VALUES > (-BINARY_FLOAT_INFINITY, -10); 1 row inserted. Command> SELECT ABS (col1) FROM abstest; < INF > 1 row found. Command> SELECT ABS (col2) FROM abstest; < 10 > 1 row found.
The ADD_MONTHS
function returns the date resulting from date
plus integer
months.
ADD_MONTHS
has the parameters:
Parameter | Description |
---|---|
Date |
A datetime value or any value that can be converted to a datetime value. |
Integer |
An integer or any value that can be converted to an integer. |
The return type is always DATE
regardless of the data type of date.
Supported data types are DATE
, TIMESTAMP
, ORA_TIMESTAMP
and ORA_DATE
.
Data types TIME
, TT_TIME
, TT_DATE
and TT_TIMESTAMP
are not supported.
If date
is the last day of the month or if the resulting month has fewer days than the day component of date
, then the result is the last day of the resulting month. Otherwise, the result has the same day component as date
.
Call the ADD_MONTHS
function to add 1 month to date January 31, 2007. The last day of February is returned.
Command> SELECT ADD_MONTHS (DATE '2007-01-31', 1) FROM dual; < 2007-02-28 00:00:00 > 1 row found.
ADD_MONTHS
returns data type DATE
if date
is of type TIMESTAMP
:
Command> DESCRIBE SELECT ADD_MONTHS (TIMESTAMP '2007-01-31 > 10:00:00', 1) FROM dual; Prepared Statement: Columns: EXP DATE NOT NULL
Use the HR
schema to select the first 5 rows of the employees
table, showing employee_id
, last_name
and hire_date
. Create new table temp_hire_date
using the CREATE TABLE ... AS SELECT
statement. Call ADD_MONTHS
to add 23 months to the original hire_date
.
Command> SELECT FIRST 5 employee_id, last_name, hire_date FROM employees; < 100, King, 1987-06-17 00:00:00 > < 101, Kochhar, 1989-09-21 00:00:00 > < 102, De Haan, 1993-01-13 00:00:00 > < 103, Hunold, 1990-01-03 00:00:00 > < 104, Ernst, 1991-05-21 00:00:00 > 5 rows found. Command> CREATE TABLE temp_hire_date (employee_id, last_name, > hire_date) AS SELECT FIRST 5 employee_id, last_name, > ADD_MONTHS (hire_date, 23) FROM employees; 5 rows inserted. Command> SELECT * FROM temp_hire_date; < 100, King, 1989-05-17 00:00:00 > < 101, Kochhar, 1991-08-21 00:00:00 > < 102, De Haan, 1994-12-13 00:00:00 > < 103, Hunold, 1991-12-03 00:00:00 > < 104, Ernst, 1993-04-21 00:00:00 > 5 rows found.
The ASCIISTR
function takes as its argument, either a string or any expression that resolves to a string, in any character set, and returns the ASCII version of the string in the database character set. Non-ASCII characters are converted to Unicode escapes.
ASCIISTR
has the parameter:
Parameter | Description |
---|---|
[N]'String' |
The string or expression that evaluates to a string that is passed to the ASCIISTR function. The string can be in any character set. Value can be of any supported character data types including CHAR , VARCHAR , VARCHAR2 , NCHAR , NVARCHAR , NVARCHAR2 , CLOB , or NCLOB data types. Both TimesTen and Oracle Database data types are supported. The ASCII version of the string in the database character set is returned. Specify N if you want to pass the string in UTF-16 format. |
The ASCIISTR
function enables you to see the representation of a string value that is not in the database character set.
The following example invokes the ASCIISTR
function passing as an argument the string 'Aäa'
in UTF-16 format. The ASCII version is returned in the WE8ISO8859P1
character set. The non-ASCII character ä
is converted to Unicode encoding value:
Command> connect "dsn=test; ConnectionCharacterSet= WE8ISO8859P1"; Connection successful: DSN=test;UID=user1;DataStore=/datastore/user1/test; DatabaseCharacterSet=WE8ISO8859P1; ConnectionCharacterSet=WE8ISO8859P1;PermSize=32;TypeMode=0; (Default setting AutoCommit=1) Command> SELECT ASCIISTR (n'Aäa') FROM dual; < A\00E4a > 1 row found.
Computes the arithmetic mean of the values in the argument. Null values are ignored.
AVG
has the following parameters:
Parameter | Description |
---|---|
Expression |
Can be any numeric data type or any nonnumeric data type that can be implicitly converted to a numeric data type. |
ALL |
Includes duplicate rows in the argument of an aggregate function. If neither ALL nor DISTINCT is specified, ALL is assumed. |
DISTINCT |
Eliminates duplicate column values from the argument of an aggregate function. |
OVER ([ AnalyticClause ]) |
If specified, indicates aggregate analytic function. For more information on analytic functions, see "Analytic functions". |
If AVG
is computed over an empty table in which GROUP BY
is not used, then AVG
returns NULL
.
If AVG
is computed over an empty group or an empty grouped table (GROUP BY
is used), AVG
returns nothing.
AVG
is evaluated as SUM
/COUNT
. The result data type is derived using the rule that is applied for the DIV
operator.
If you do not specify the AnalyticClause
in your query, then AVG
acts as an aggregate function.
If you specify DISTINCT
and the AnalyticClause
, then you can only specify the QueryPartitionClause
. The OrderByClause
and WindowingClause
are not allowed.
Enables you to convert data of one type to another type. CAST
can be used wherever a constant can be used. CAST
is useful in specifying the exact data type for an argument. This is especially true for unary operators like '-
' or functions with one operand like TO_CHAR
or TO_DATE
.
A value can only be CAST
to a compatible data type, with the exception of NULL
. NULL
can be cast to any data type. CAST
is not needed to convert a NULL
literal to the desired target type.
The following conversions are supported:
Numeric value to numeric or BCD (Binary Coded Decimal)
NCHAR
to NCHAR
CHAR
string to BINARY
string or DATE
, TIME
or TIMESTAMP
BINARY
string to BINARY
or CHAR
string
DATE
, TIME
or TIMESTAMP
to CHAR
CAST
has the parameters:
Parameter | Description |
---|---|
Expression |
Specifies the value to be converted. |
AS DataType |
Specifies the resulting data type. |
CAST
to a domain name is not supported.
Casting a selected value may cause the SELECT
statement to take more time and memory than a SELECT
statement without a CAST
expression.
The CHR
function returns the character having the specified binary value in the database character set.
CHR
has the parameter:
Parameter | Description |
---|---|
n |
The binary value in the database character set. The character having this binary value is returned. The result is of type VARCHAR2 . |
For single-byte character sets, if n
>256, then TimesTen returns the binary value of n
mod 256.
For multibyte character sets, n
must resolve to one code point. Invalid code points are not validated. If you specify an invalid code point, the result is indeterminate.
The CEIL
function returns the smallest integer greater than or equal to Expression
.
CEIL
has the parameter:
Parameter | Description |
---|---|
Expression |
Operand or column can be any numeric data type. |
If Expression
is of type TT_DECIMAL
or NUMBER
, the data type returned is NUMBER
with maximum precision and scale. Otherwise, CEIL
returns the same data type as the numeric data type of Expression
.
If the value of Expression
is NULL
, NULL
is returned. If the value of Expression
is -INF
, INF
, or NaN
, the value returned is -INF
, INF
, or NaN
respectively.
Sum the commission_pct
for employees in the employees
table, and then call CEIL
to return the smallest integer greater than or equal to the value returned by SUM
. You see the value returned by the SUM
function is 7.8 and the value returned by the CEIL
function is 8.
Command> SELECT SUM (commission_pct) FROM employees; < 7.8 > 1 row found. Command> SELECT CEIL (SUM (commission_pct)) FROM employees; < 8 > 1 row found.
The COALESCE
function returns the first non-null expression
in the expression list. If all occurrences of expression
evaluate to NULL
, then the function returns NULL
.
COALESCE
has the parameters:
Parameter | Description |
---|---|
Expression1, Expression2 [,...] |
The expressions in the expression list. The first non-null expression in the expression list is returned.
Each expression is evaluated in order and there must be at least two expressions. |
This function is a generalization of the NVL
function.
Use COALESCE
as a variation of the CASE expressions
. For example:
COALESCE (Expression1, Expression2)
is equivalent to:
CASE WHEN Expression1 IS NOT NULL THEN Expression1 ELSE Expression2 END
The example illustrates the use of the COALESCE
expression. The COALESCE
expression is used to return the commission_pct
for the first 10 employees with manager_id
= 100
. If the commission_pct
is NOT NULL
, then the original value for commission_pct
is returned. If commission_pct
is NULL
, then 0
is returned.
Command> SELECT FIRST 10 employee_id, COALESCE (commission_pct, 0) FROM employees WHERE manager_id = 100; < 101, 0 > < 102, 0 > < 114, 0 > < 120, 0 > < 121, 0 > < 122, 0 > < 123, 0 > < 124, 0 > < 145, .4 > < 146, .3 > 10 rows found.
The CONCAT
function concatenates one character string with another to form a new character string.
CONCAT
has the parameters:
Parameter | Description |
---|---|
Expression1 |
A CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB , or NCLOB expression. |
Expression2 |
A CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB , or NCLOB expression. |
CONCAT
returns Expression1
concatenated with Expression2
.
The type of Expression1
and Expression2
must be compatible.
If Expression2
is NULL
, CONCAT
returns Expression1
. If Expression1
is NULL
, CONCAT
returns Expression2
.
If both Expression1
and Expression2
are NULL
, CONCAT
returns NULL
.
The treatment of NCHAR
and NVARCHAR2
is similar. If one of the operands is of varying length, the result is of varying length. Otherwise the result is of a fixed length.
The return data type of CONCAT
depends on the types of Expression1
and Expression2
. In concatenations of two different data types, the database returns the data type that can contain the result. Therefore, if one of the arguments is a national character data type, the returned value is a national character data type. If one of the arguments is a LOB, the returned value is a LOB.
The following table provides examples of how the return type is determined.
Expression1 | Expression2 | CONCAT |
---|---|---|
CHAR ( m ) |
CHAR ( n ) |
CHAR ( m+n ) |
CHAR ( m ) |
VARCHAR2 ( n ) |
VARCHAR2 ( m+n ) |
VARCHAR2 ( m ) |
CHAR ( n ) |
VARCHAR2 ( m+n ) |
VARCHAR2 ( m ) |
VARCHAR2 ( n ) |
VARCHAR2 ( m+n ) |
CLOB |
NCLOB |
NCLOB |
NCLOB |
NCHAR |
NCLOB |
NCLOB |
CHAR ( n ) |
NCLOB |
NCHAR ( n ) |
CLOB |
NCLOB |
The following example concatenates first names and last names.
Command> SELECT CONCAT(CONCAT(first_name, ' '), last_name), salary FROM employees; < Steven King, 24000 > < Neena Kochhar, 17000 > < Lex De Haan, 17000 > < Alexander Hunold, 9000 > ... 107 rows found.
The following example concatenates column id
with column id2
. In this example, the result type is NCHAR(40)
.
Command> CREATE TABLE cat (id CHAR (20), id2 NCHAR (20)); Command> INSERT INTO cat VALUES ('abc', 'def'); 1 row inserted. Command> SELECT CONCAT (id,id2) FROM cat; < abc def > 1 row found.
The description of the ||
operator is in "Expression specification".
Counts all rows that satisfy the WHERE
clause, including rows containing null values. The data type of the result is TT_INTEGER
.
COUNT
is an aggregate function and can also be an aggregate analytic function. For more details on aggregate functions, see "Aggregate functions". For information on analytic functions, see "Analytic functions". For more information on the number of rows in a table, see the description for the NUMTUPS
field in "SYS.TABLES" in Oracle TimesTen In-Memory Database System Tables and Views Reference.
COUNT
has the parameters:
Parameter | Description |
---|---|
Expression |
Can be any numeric data type or any nonnumeric type that can be implicitly converted to a numeric type.
Counts all rows. Rows containing null values are not counted. The data type of the result is |
* |
Counts all rows that satisfy the WHERE clause, including duplicates and null values. COUNT never returns NULL .The data type of the result is TT_INTEGER . For more information on the number of rows in a table, see the description for the NUMTUPS field in "SYS.TABLES" in Oracle TimesTen In-Memory Database System Tables and Views Reference. |
ALL |
Includes duplicate rows in the argument of an aggregate function. If neither ALL nor DISTINCT is specified, ALL is assumed. |
DISTINCT |
Eliminates duplicate column values from the argument of an aggregate function. |
ROWID |
TimesTen assigns a unique ID called a rowid to each row stored in a table. The rowid value can be retrieved through the ROWID pseudocolumn. See "ROWID" for more details. |
OVER ([ AnalyticClause ]) |
If specified, indicates aggregate analytic function. For more information on analytic functions, see "Analytic functions". |
If an aggregate function is computed over an empty table in which GROUP BY
is not used, COUNT
returns 0.
If an aggregate function is computed over an empty group or an empty grouped table (GROUP BY
is used), COUNT
returns nothing.
If you do not use the AnalyticClause
in your query, then COUNT
acts as an aggregate function.
If you specify DISTINCT
and the AnalyticClause
, then you can only specify the QueryPartitionClause
. The OrderByClause
and WindowingClause
are not allowed.
Count the number of employees.
Command> SELECT COUNT(*) "TOTAL EMP" FROM employees; TOTAL EMP < 107 > 1 row found.
Count the number of managers by selecting out each individual manager ID without duplication.
Command> SELECT COUNT(DISTINCT manager_id) "Managers" FROM employees; MANAGERS < 18 > 1 row found.
The DECODE
function compares an expression to each search value one by one. If the expression is equal to the search value, the result value is returned. If no match is found, then the default value (if specified) is returned. Otherwise NULL
is returned.
DECODE
has the parameters:
Parameter | Description |
---|---|
Expression |
The expression that is compared to the search value. Expression can be CHAR , VARCHAR2 , NCHAR , or NVARCHAR2 data types. Both TimesTen and Oracle Database data types are supported. |
SearchValue |
An expression is compared to one or more search values. |
Result |
If the expression is equal to a SearchValue , the specified Result value is returned. |
Default |
If no match is found, the default value is returned. Default is optional. If Default is not specified and no match is found, then NULL is returned. |
The following example invokes the DECODE
function. In the locations
table, if the column country_id
is equal to 'IT'
, the function returns 'Italy'
. If the country_id
is equal to 'JP'
, the function returns 'Japan'
. If the country_id
is equal to 'US'
, 'United States'
is returned. If the country_id
is not equal to 'IT'
or 'JP'
or 'US'
, the function returns 'Other'
.
Command> SELECT location_id, > DECODE (country_id, 'IT', 'Italy', > 'JP', 'Japan', 'US', 'United States', 'Other') > FROM locations WHERE location_id < 2000; LOCATION_ID, EXP < 1000, Italy > < 1100, Italy > < 1200, Japan > < 1300, Japan > < 1400, United States > < 1500, United States > < 1600, United States > < 1700, United States > < 1800, Other > < 1900, Other > 10 rows found.
The DENSE_RANK
function is an analytic function that computes the rank of rows in an ordered group of rows and returns the ranks as type NUMBER
.
Parameter | Description |
---|---|
QueryPartitionClause |
For information on syntax, semantics, and restrictions, see "Analytic functions". |
OrderByClause |
For information on syntax, semantics, and restrictions, see "Analytic functions". |
The ranks are consecutive integers beginning with 1. The largest rank value is the number of unique values returned by the query. Rank values are not skipped in the event of ties. Rows with equal values for the ranking criteria receive the same rank.
DENSE_RANK
computes the rank of each row returned from a query with respect to the other rows, based on the values of the Expressions
in the OrderByClause
.
Select the department name, employee name, and salary of all employees who work in the human resources or purchasing department. Compute a rank for each unique salary in each of the two departments. The salaries that are equal receive the same rank.
Command> SELECT d.department_name, e.last_name, e.salary, DENSE_RANK() > OVER (PARTITION BY e.department_id ORDER BY e.salary) AS dense > FROM employees e, departments d > WHERE e.department_id = d.department_id > AND d.department_id IN ('30', '40') > ORDER BY e.last_name, e.salary, d.department_name, dense; < Purchasing, Baida, 2900, 4 > < Purchasing, Colmenares, 2500, 1 > < Purchasing, Himuro, 2600, 2 > < Purchasing, Khoo, 3100, 5 > < Human Resources, Mavris, 6500, 1 > < Purchasing, Raphaely, 11000, 6 > < Purchasing, Tobias, 2800, 3 > 7 rows found.
A BLOB
column can be initialized to a zero-length, empty BLOB
using the EMPTY_BLOB
function. This function initializes the LOB to a non-null value, so can be used for initializing any BLOB
that has been declared as NOT NULL
.
You can only use EMPTY_BLOB
in the VALUES
clause of an INSERT
statement or the SET
clause of an UPDATE
statement.
The following example uses the EMPTY_BLOB
function to initialize a non-null BLOB
column to a zero-length value.
Command> CREATE TABLE blob_content ( > id NUMBER PRIMARY KEY, > blob_column BLOB NOT NULL); -- Does not allow a NULL value Command> INSERT INTO blob_content (id, blob_column) > VALUES (1, EMPTY_BLOB( ) ); 1 row inserted.
A CLOB
or NCLOB
column can be initialized to a zero-length, empty CLOB
or NCLOB
using the EMPTY_CLOB
function. Both CLOB
and NCLOB
data types are initialized with the EMPTY_CLOB
function. This function initializes the LOB to a non-null value, so can be used for initializing any CLOB
or NCLOB
that has been declared as NOT NULL
.
You can only use EMPTY_CLOB
in the VALUES
clause of an INSERT
statement or the SET
clause of an UPDATE
statement.
The following example uses the EMPTY_CLOB
function to initialize a non-null CLOB
column to a zero-length value.
Command> CREATE TABLE clob_content ( > id NUMBER PRIMARY KEY, > clob_column CLOB NOT NULL ); -- This definition does not allow a NULL value Command> INSERT INTO clob_content (id, clob_column) > VALUES (1, EMPTY_CLOB( ) ); 1 row inserted.
The EXTRACT
function extracts and returns the value of a specified datetime field from a datetime or interval value expression as a NUMBER
data type. This function can be useful for manipulating datetime field values in very large tables.
If you are using TimesTen type mode, see the Oracle TimesTen In-Memory Database Release 6.0.3 documentation for information about the EXTRACT
function.
EXTRACT
has the following parameters:
Parameter | Description |
---|---|
DateTimeField |
The field to be extracted from IntervalExpression or DateTimeExpression . Accepted fields are YEAR , MONTH , DAY , HOUR , MINUTE or SECOND . |
IntervalExpression |
An interval result. |
DateTimeExpression |
A datetime expression. For example, TIME , DATE , TIMESTAMP . |
Some combinations of DateTimeField
and DateTimExpression
or IntervalExpression
result in ambiguity. In these cases, TimesTen returns UNKNOWN
.
The field you are extracting must be a field of the IntervalExpression
or DateTimeExpression
. For example, you can extract only YEAR
, MONTH
, and DAY
from a DATE
value. Likewise, you can extract HOUR
, MINUTE
or SECOND
only from the TIME
, DATE
, or TIMESTAMP
data type.
The fields are extracted into a NUMBER
value.
The following example extracts the second field out of the interval result sysdate-t1.createtime
.
SELECT EXTRACT(SECOND FROM sysdate-t1.createtime) FROM t1;
The following example extracts the second field out of sysdate
from the dual
system table.
Command> SELECT EXTRACT (SECOND FROM sysdate) FROM dual; < 20 > 1 row found.
The FIRST_VALUE
function is an analytic function that returns the first value in an ordered set of values.
Parameter | Description |
---|---|
Expression |
For information on supported Expressions , see "Analytic functions". |
IGNORE NULLS |
Specify IGNORE NULLS if you want FIRST_VALUE to return the first non-null value in the set or NULL if all values in the set are NULL . Clause is optional. |
OVER ( AnalyticClause ) |
For information on syntax, semantics, and restrictions, see "Analytic functions". |
If the first value in the set is NULL
, then FIRST_VALUE
returns NULL
unless you specify IGNORE NULLS
. Specify IGNORE NULLS
if you want the function to return the first non-null value in the set or NULL
if all values in the set are NULL
.
Use the FIRST_VALUE
function to select for each employee in department 90, the last name of the employee with the lowest salary.
Command> SELECT department_id, last_name, salary, FIRST_VALUE (last_name) OVER > (ORDER BY salary ASC ROWS UNBOUNDED PRECEDING) AS lowest_sal > FROM > (SELECT * FROM employees WHERE department_id = 90 ORDER BY employee_id) > ORDER BY department_id, last_name, salary, lowest_sal; < 90, De Haan, 17000, Kochhar > < 90, King, 24000, Kochhar > < 90, Kochhar, 17000, Kochhar > 3 rows found.
The FLOOR
function returns the largest integer equal to or less than Expression
.
FLOOR
has the parameter:
Parameter | Description |
---|---|
Expression |
Operand or column can be any numeric data type. |
If Expression
is of type TT_DECIMAL
or NUMBER
, the data type returned is NUMBER
with maximum precision and scale. Otherwise, FLOOR
returns the same data type as the numeric data type of Expression
.
If the value of Expression
is NULL
, NULL
is returned. If the value of Expression
is -INF
, INF
, or NaN
, the value returned is -INF
, INF
, or NaN
respectively.
Sum the commission_pct
for employees in the employees
table. Then call FLOOR
to return the largest integer equal to or less than the value returned by SUM
. You see the value returned by the SUM
function is 7.8
and the value returned by the FLOOR
function is 7:
Command> SELECT SUM (commission_pct) FROM employees; < 7.8 > 1 row found. Command> SELECT FLOOR (SUM (commission_pct)) FROM employees; < 7 > 1 row found.
The GREATEST
function returns the greatest of the list of one or more expressions.
GREATEST
has the parameter:
Parameter | Description |
---|---|
Expression [,...] |
List of one or more expressions that is evaluated to determine the greatest expression value. Operand or column can be numeric, character or date. Each expression in the list must be from the same data type family. |
Each expression in the list must be from the same data type family or date subfamily. Data type families include numeric, character and date. The date family includes four subfamilies: date family, TIME
family, TT_DATE
family, and TT_TIMESTAMP
family. As an example, do not specify a numeric expression and a character expression in the list of expressions. Similarly, do not specify a date expression and a TT_TIMESTAMP
expression in the list of expressions.
If the first Expression
is numeric, then TimesTen determines the argument with the highest numeric precedence, implicitly converts the remaining arguments to that data type before the comparison, and returns that data type.
If the first Expression
is in the character family, and the operand or column is of type CHAR
or VARCHAR2
, the data type returned is VARCHAR2
. If the operand or column is of type NCHAR
or NVARCHAR2
, the data type returned is NVARCHAR2
. The returned data type length is equal to the length of the largest expression. If one operand or column is of type CHAR
or VARCHAR2
and the second operand or column is of type NCHAR
or NVARCHAR2
, the data type returned is NVARCHAR2
.
TimesTen uses nonpadded comparison semantics for data types from the character family.
If the first expression is in the date family, the data type returned is the same data type as the first expression.
If any of the expressions is NULL
, the result is NULL
.
If the first Expression
is in the character family, and the operand or column is of type TT_CHAR
or TT_VARCHAR
, the data type returned is TT_VARCHAR
. If the operand or column is of type TT_NCHAR
or TT_NVARCHAR
, the data type returned is TT_NVARCHAR
. The returned data type length is equal to the largest of the expressions.
You can specify a maximum of 256 expressions.
Use the GREATEST
function to return the string with the greatest value:
Command> SELECT GREATEST ('GREAT', 'GREATER', 'GREATEST') FROM dual; < GREATEST > 1 row found.
Use the GREATEST
function to return the numeric expression with the greatest value. In this example, BINARY_DOUBLE
is the data type with the highest numeric precedence, so arguments are implicitly converted to BINARY_DOUBLE
before the comparison and the data type BINARY_DOUBLE
is returned:
Command> SELECT GREATEST (10, 10.55, 10.1D) FROM dual; < 10.5500000000000 > 1 row found.
Use the DESCRIBE
command to confirm the data type returned is BINARY_DOUBLE
:
Command> DESCRIBE SELECT GREATEST (10, 10.55, 10.1D) FROM dual; Prepared Statement: Columns: EXP BINARY_DOUBLE NOT NULL
Use the GREATEST
function to return the DATE
expression with the greatest value. DATE
and TIMESTAMP
are in the same date family.
Command> SELECT GREATEST (DATE '2007-09-30', > TIMESTAMP '2007-09-30:10:00:00') FROM dual; < 2007-09-30 10:00:00 > 1 row found.
Attempt to use the GREATEST
function to return the greatest value in the list of TT_DATE
and TT_TIMESTAMP
expressions. You see an error because TT_DATE
and TT_TIMESTAMP
are in different date subfamilies and cannot be used in the same list of expressions.
Command> SELECT GREATEST (TT_DATE '2007-09-30', TT_TIMESTAMP > '2007-09-30:10:00:00') FROM dual; 2817: Invalid data type TT_TIMESTAMP for argument 2 for function GREATEST The command failed.
Use the GREATEST
function to return the TT_DATE
expression with the greatest value.
Command> SELECT GREATEST (TT_DATE '2007-09-30', > TT_DATE '2007-09-29', TT_DATE '2007-09-28') FROM dual; < 2007-09-30 > 1 row found.
The GROUP_ID
function identifies duplicate groups in a SELECT
query resulting from a GROUP
BY
clause. This function returns the number 0 for a unique group; any subsequent duplicate grouping row receives a higher number, starting with 1. The GROUP_ID
function filters out duplicate groupings from the query result. If you have complicated queries that may generate duplicate values, you can eliminate those rows by including the HAVING GROUP_ID() = 0
condition.
Note:
For full details on theGROUP BY
clause, see "GROUP BY clause". For details on the HAVING
clause, see "SELECT".The GROUP_ID
function is applicable only in a SELECT
statement that contains a GROUP BY
clause; it can be used in the select list and HAVING
clause of the SELECT
query.
GROUP_ID()
The following example shows how GROUP_ID
returns 0 for a unique group and a number > 0 to identify duplicate groups. The following example prints out the department number, manager id and the sum of the salary within the manager. The resulting output is grouped using the ROLLUP
clause on the manager and department providing superaggregate results.
Command> SELECT department_id as DEPT, manager_id AS MGR, GROUP_ID(), SUM(salary) as SALARY FROM employees WHERE manager_id > 146 GROUP BY manager_id, ROLLUP(manager_id, department_id) ORDER BY manager_id, department_id; DEPT, MGR, EXP, SALARY < 80, 147, 0, 46600 > < <NULL>, 147, 1, 46600 > < <NULL>, 147, 0, 46600 > < 80, 148, 0, 51900 > < <NULL>, 148, 0, 51900 > < <NULL>, 148, 1, 51900 > < 80, 149, 0, 43000 > < <NULL>, 149, 0, 7000 > < <NULL>, 149, 0, 50000 > < <NULL>, 149, 1, 50000 > < 20, 201, 0, 6000 > < <NULL>, 201, 0, 6000 > < <NULL>, 201, 1, 6000 > < 110, 205, 0, 8300 > < <NULL>, 205, 0, 8300 > < <NULL>, 205, 1, 8300 > 16 rows found.
The GROUPING
function enables you to determine whether a NULL
is a stored NULL
or an indication of a subtotal or grand total. Using a single column as its argument, GROUPING
returns a 1 when it encounters a null value created by a ROLLUP
or CUBE
operation, indicating a subtotal or grand total. Any other type of value, including a stored NULL
, returns a 0.
The GROUPING
function is applicable only in a SELECT
statement that contains a GROUP BY
clause. It can be used in the select list and HAVING
clause of the SELECT
query that includes the GROUP BY
clause. The expression indicated in the GROUPING
function syntax must match one of the expressions contained in the GROUP BY
clause.
The following syntax uses GROUPING
to identify the results from the expression listed as an aggregate or not:
SELECT ... [GROUPING(Expression) ... ] ... GROUP BY ... { RollupCubeClause | GroupingSetsClause } ...
The following syntax uses GROUPING
within a HAVING
clause to identify the results from the expression listed as an aggregate or not:
SELECT ... GROUP BY ... { RollupCubeClause | GroupingSetsClause } ... HAVING GROUPING(Expression) = 1
Parameter | Description |
---|---|
Expression |
Valid expression syntax. See Chapter 3, "Expressions". |
RollupCubeClause |
The GROUP BY clause may include one or more ROLLUP or CUBE clauses. See "GROUP BY clause" for full details. |
GroupingSetsClause |
The GROUP BY clause may include one or more GROUPING SETS clauses. The GROUPING SETS clause enables you to explicitly specify which groupings of data that the database returns. For more information, see "GROUPING SETS". |
The following example shows how the grouping function returns a '1' when it encounters the grand total for the department.
Command> SELECT department_id AS DEPT, GROUPING(department_id) AS DEPT_GRP, SUM(salary) AS SALARY FROM emp_details_view GROUP BY ROLLUP(department_id) ORDER BY department_id; DEPT, DEPT_GRP, SALARY < 10, 0, 4400 > < 20, 0, 19000 > < 30, 0, 24900 > < 40, 0, 6500 > < 50, 0, 156400 > < 60, 0, 28800 > < 70, 0, 10000 > < 80, 0, 304500 > < 90, 0, 58000 > < 100, 0, 51600 > < 110, 0, 20300 > < <NULL>, 1, 684400 > 12 rows found.
The following example shows that you can use the GROUPING
function for each column to determine which null values are for the totals.
Command> SELECT department_id AS DEPT, job_id AS JOB, GROUPING(department_id) AS DEPT_GRP, GROUPING(job_id) AS JOB_GRP, GROUPING_ID(department_id, job_id) AS GRP_ID, SUM(salary) AS SALARY FROM emp_details_view GROUP BY CUBE(department_id, job_id) ORDER BY department_id, job_id, grp_id ASC; DEPT, JOB, DEPT_GRP, JOB_GRP, GRP_ID, SALARY < 10, AD_ASST, 0, 0, 0, 4400 > < 10, <NULL>, 0, 1, 1, 4400 > < 20, MK_MAN, 0, 0, 0, 13000 > < 20, MK_REP, 0, 0, 0, 6000 > < 20, <NULL>, 0, 1, 1, 19000 > < 30, PU_CLERK, 0, 0, 0, 13900 > < 30, PU_MAN, 0, 0, 0, 11000 > < 30, <NULL>, 0, 1, 1, 24900 > ... < 110, AC_ACCOUNT, 0, 0, 0, 8300 > < 110, AC_MGR, 0, 0, 0, 12000 > < 110, <NULL>, 0, 1, 1, 20300 > < <NULL>, AC_ACCOUNT, 1, 0, 2, 8300 > < <NULL>, AC_MGR, 1, 0, 2, 12000 > < <NULL>, AD_ASST, 1, 0, 2, 4400 > < <NULL>, AD_PRES, 1, 0, 2, 24000 > < <NULL>, AD_VP, 1, 0, 2, 34000 > < <NULL>, FI_ACCOUNT, 1, 0, 2, 39600 > < <NULL>, FI_MGR, 1, 0, 2, 12000 > < <NULL>, HR_REP, 1, 0, 2, 6500 > < <NULL>, IT_PROG, 1, 0, 2, 28800 > < <NULL>, MK_MAN, 1, 0, 2, 13000 > < <NULL>, MK_REP, 1, 0, 2, 6000 > < <NULL>, PR_REP, 1, 0, 2, 10000 > < <NULL>, PU_CLERK, 1, 0, 2, 13900 > < <NULL>, PU_MAN, 1, 0, 2, 11000 > < <NULL>, SA_MAN, 1, 0, 2, 61000 > < <NULL>, SA_REP, 1, 0, 2, 243500 > < <NULL>, SH_CLERK, 1, 0, 2, 64300 > < <NULL>, ST_CLERK, 1, 0, 2, 55700 > < <NULL>, ST_MAN, 1, 0, 2, 36400 > < <NULL>, <NULL>, 1, 1, 3, 684400 > 50 rows found.
The GROUPING_ID
function returns a number that shows the exact GROUP BY
level of aggregation resulting from a ROLLUP
or CUBE
clause.
The GROUPING_ID
function takes the ordered list of grouping columns from the ROLLUP
or CUBE
as input and computes the grouping ID as follows:
Applies the GROUPING
function to each of the individual columns in the list. The result is a set of ones and zeros, where 1 represents a superaggregate generated by the ROLLUP
or CUBE
.
Puts these ones and zeros in the same order as the order of the columns in its argument list to produce a bit vector.
Converts this bit vector from a binary number into a decimal (base 10) number, which is returned as the grouping ID.
For instance, if you group with CUBE(department_id, job_id)
, the returned values are as shown in Table 4-1.
Table 4-1 GROUPING_ID Example for CUBE(department_id, job_id)
Aggregation Level | Bit Vector | GROUPING_ID |
---|---|---|
Normal grouping rows for department and job |
0 0 |
0 |
Subtotal for |
0 1 |
1 |
Subtotal for |
1 0 |
2 |
Grand total |
1 1 |
3 |
The GROUPING_ID
function can be used in a query to filter rows so that only the summary rows are displayed. You can use the GROUPING_ID
function in the HAVING
clause to restrict output to only those rows that contain totals and subtotals. This can be accomplished when adding a comparison of the GROUPING_ID
function results as greater than zero in the HAVING
clause.
The GROUPING_ID
function is applicable only in a SELECT
statement that contains the GROUP BY
clause, a GROUPING
function, and one of the following clauses: ROLLUP
, CUBE
or GROUPING SETS
clauses. It can be used in the select list and HAVING
clause of the SELECT
query.
GROUPING_ID(Expression [, Expression ]...)
Parameter | Description |
---|---|
Expression |
Valid expression syntax. See Chapter 3, "Expressions". |
The following example has the HAVING
clause filter on the GROUPING_ID
function, where the returned value is greater than zero. This excludes rows that do not contain either a subtotal or grand total. The following example shows the subtotals for the departments are identified with a group ID of 1, subtotals for the job ID with a group ID of 2 and the grand total with a group ID of 3:
Command> SELECT department_id AS DEPT, job_id AS JOB, GROUPING_ID(department_id, job_id) AS GRP_ID, SUM(salary) AS SALARY FROM emp_details_view GROUP BY CUBE(department_id, job_id) HAVING GROUPING_ID(department_id, job_id) > 0 ORDER BY department_id, job_id, grp_id ASC; DEPT, JOB, GRP_ID, SALARY < 10, <NULL>, 1, 4400 > < 20, <NULL>, 1, 19000 > < 30, <NULL>, 1, 24900 > < 40, <NULL>, 1, 6500 > < 50, <NULL>, 1, 156400 > < 60, <NULL>, 1, 28800 > < 70, <NULL>, 1, 10000 > < 80, <NULL>, 1, 304500 > < 90, <NULL>, 1, 58000 > < 100, <NULL>, 1, 51600 > < 110, <NULL>, 1, 20300 > < <NULL>, AC_ACCOUNT, 2, 8300 > < <NULL>, AC_MGR, 2, 12000 > < <NULL>, AD_ASST, 2, 4400 > < <NULL>, AD_PRES, 2, 24000 > < <NULL>, AD_VP, 2, 34000 > < <NULL>, FI_ACCOUNT, 2, 39600 > < <NULL>, FI_MGR, 2, 12000 > < <NULL>, HR_REP, 2, 6500 > < <NULL>, IT_PROG, 2, 28800 > < <NULL>, MK_MAN, 2, 13000 > < <NULL>, MK_REP, 2, 6000 > < <NULL>, PR_REP, 2, 10000 > < <NULL>, PU_CLERK, 2, 13900 > < <NULL>, PU_MAN, 2, 11000 > < <NULL>, SA_MAN, 2, 61000 > < <NULL>, SA_REP, 2, 243500 > < <NULL>, SH_CLERK, 2, 64300 > < <NULL>, ST_CLERK, 2, 55700 > < <NULL>, ST_MAN, 2, 36400 > < <NULL>, <NULL>, 3, 684400 > 31 rows found.
Determines the first position, if any, at which one string occurs within another. If the substring does not occur in the string, 0
is returned. The position returned is always relative to the beginning of SourceExpr
. INSTR
returns type NUMBER
.
If you are using TimesTen type mode, for information on the INSTR
function, see the Oracle TimesTen In-Memory Database Release 6.0.3 documentation.
INSTR
has the parameters:
Parameter | Description |
---|---|
SourceExpr |
The string to be searched to find the position of SearchExpr. Value can be any supported character data types including CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB , or NCLOB data types. Both TimesTen and Oracle Database data types are supported. |
SearchExpr |
The substring to be found in string SourceExpr. If SearchExpr does not occur in SourceExpr , zero is returned. If either string is of length zero, NULL is returned. |
m |
The optional position at which to begin the search. If m is specified as zero, the result is zero. If m is positive, the search begins at the CharExpr2 +m . If m is negative, the search begins m characters from the end of CharExpr2 . |
n |
If n is specified it must be a positive value and the search returns the position of the n th occurrence of CharExpr1 . |
INSTR
calculates strings using characters as defined by character set. INSTRB
uses bytes instead of characters. INSTR4
uses UCS4 code points.
The following example uses INSTR
to determine the position at which the substring 'ing'
occurs in the string 'Washington'
:
Command> SELECT INSTR ('Washington', 'ing') FROM dual; < 5 > 1 row found.
The following example uses INSTR
to provide the number of employees with a '650' area code as input to the COUNT
function:
Command> SELECT COUNT(INSTR(phone_number, '650')) FROM employees; < 107 > 1 row found.
The LAST_VALUE
function is an analytic function that returns the last value in an ordered set of values.
Parameter | Description |
---|---|
Expression |
For information on supported Expressions , see "Analytic functions". |
IGNORE NULLS |
Specify IGNORE NULLS if you want LAST_VALUE to return the last non-NULL value in the set or NULL if all values in the set are NULL. Clause is optional. |
OVER ( AnalyticClause ) |
For information on syntax, semantics, and restrictions, see "Analytic functions". |
If the last value in the set is NULL
, then LAST_VALUE
returns NULL
unless you specify IGNORE NULLS
. Specify IGNORE NULLS
if you want the function to return the last non-null value in the set or NULL
if all values in the set are NULL
.
Use the LAST_VALUE
function to return for each row the hire date of the employee with the highest salary.
Command> SELECT last_name, salary, hire_date, > LAST_VALUE (hire_date) OVER (ORDER BY salary > ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS lv > FROM > (SELECT * FROM employees WHERE department_id = 90 ORDER BY hire_date) > ORDER BY last_name, salary, hire_date, lv; < De Haan, 17000, 1993-01-13 00:00:00, 1987-06-17 00:00:00 > < King, 24000, 1987-06-17 00:00:00, 1987-06-17 00:00:00 > < Kochhar, 17000, 1989-09-21 00:00:00, 1987-06-17 00:00:00 > 3 rows found.
The LEAST
function returns the smallest of the list of one or more expressions.
LEAST
has the parameter:
Parameter | Description |
---|---|
Expression [,...] |
List of one or more expressions that is evaluated to determine the smallest expression value. Operand or column can be numeric, character, or date. Each expression in the list must be from the same data type family. |
Each expression in the list must be from the same data type family or date subfamily. Data type families include numeric, character and date. The date family includes four subfamilies: date family, TIME
family, TT_DATE
family, and TT_TIMESTAMP
family. As an example, do not specify a numeric expression and a character expression in the list of expressions. Similarly, do not specify a date expression and a TT_TIMESTAMP
expression in the list of expressions.
If the first Expression
is numeric, then TimesTen determines the argument with the highest numeric precedence, implicitly converts the remaining arguments to that data type before the comparison, and returns that data type.
If the first Expression
is in the character family, and the operand or column is of type CHAR
or VARCHAR2
, the data type returned is VARCHAR2
. If the operand or column is of type NCHAR
or NVARCHAR2
, the data type returned is NVARCHAR2
. The returned data type length is equal to the length of the largest expression. If one operand or column is of type CHAR
or VARCHAR2
and the second operand or column is of type NCHAR
or NVARCHAR2
, the data type returned is NVARCHAR2
.
TimesTen uses nonpadded comparison semantics for data types from the character family.
If the first expression is in the date family, the data type returned is the same data type as the first expression.
If any of the expressions is NULL
, the result is NULL
.
If the first Expression
is in the character family, and the operand or column is of type TT_CHAR
or TT_VARCHAR
, the data type returned is TT_VARCHAR
. If the operand or column is of type TT_NCHAR
or TT_NVARCHAR
, the data type returned is TT_NVARCHAR
. The returned data type length is equal to the largest of the expressions.
You can specify a maximum of 256 expressions.
Use the LEAST
function to return the string with the smallest value:
Command> SELECT LEAST ('SMALL','SMALLER','SMALLEST') FROM dual; < SMALL > 1 row found.
Use the LEAST
function to return the numeric expression with the smallest value. In this example, NUMBER
is the data type with the highest numeric precedence, so arguments are implicitly converted to NUMBER
before the comparison and the data type NUMBER
is returned. First describe the table leastex
to see the data types defined for columns col1
and col2
. Then SELECT *
from leastex
to see the data. Then invoke the LEAST
function.
Command> DESCRIBE leastex; Table SAMPLEUSER.LEASTEX: Columns: COL1 NUMBER (2,1) COL2 TT_BIGINT 1 table found. (primary key columns are indicated with *) Command> SELECT * FROM leastex; < 1.1, 1 > 1 row found. Command> SELECT LEAST (Col2,Col1) from leastex; < 1 > 1 row found.
Use the DESCRIBE
command to confirm that the data type returned is NUMBER
:
Command> DESCRIBE SELECT LEAST (Col2,Col1) FROM leastex; Prepared Statement: Columns: EXP NUMBER
Use the LEAST
function to return the DATE
expression with the smallest value. DATE
and TIMESTAMP
are in the same date family.
Command> SELECT LEAST (DATE '2007-09-17', > TIMESTAMP '2007-09-17:10:00:00') FROM dual; < 2007-09-17 00:00:00 > 1 row found.
Attempt to use the LEAST
function to return the smallest value in the list of TT_DATE
and TT_TIMESTAMP
expressions. You see an error because TT_DATE
and TT_TIMESTAMP
are in different date subfamilies and cannot be used in the same list of expressions.
Command> SELECT LEAST (TT_DATE '2007-09-17', > TT_TIMESTAMP '2007-09-17:01:00:00') FROM dual; 2817: Invalid data type TT_TIMESTAMP for argument 2 for function LEAST The command failed.
Use the LEAST
function to return the TIME
expression with the smallest value.
Command> SELECT LEAST (TIME '13:59:59', TIME '13:59:58', > TIME '14:00:00') FROM dual; < 13:59:58 > 1 row found.
Returns the length of a given character string in an expression. LENGTH
returns type NUMBER
.
If you are using TimesTen type mode, for information on the LENGTH
function, see the Oracle TimesTen In-Memory Database Release 6.0.3 documentation.
LENGTH
has the parameter:
Parameter | Description |
---|---|
CharExpr |
The string for which to return the length. Supported data types for CharExpr for are CHAR , VARCHAR2 , NCHAR , or NVARCHAR2 . LENGTH and LENGTHB also support CLOB , NCLOB , and BLOB data types. |
The LENGTH
functions return the length of CharExpr
. LENGTH
calculates the length using characters as defined by the character set. LENGTHB
uses bytes rather than characters. LENGTH4
uses UCS4 code points.
Determine the length of the string 'William'
:
Command> SELECT LENGTH('William') FROM dual; < 7 > 1 row found.
The following determines the length of the NCLOB
data:
Command> SELECT nclob_column FROM nclob_content; < Demonstration of the NCLOB data type > 1 row found. Command> SELECT LENGTH(nclob_column) FROM nclob_content; < 36 > 1 row found.
The LOWER
function converts expressions of type CHAR
, NCHAR
, VARCHAR2
, NVARCHAR2
, CLOB
, or NCLOB
to lowercase. The UPPER
function converts expressions of type CHAR
, NCHAR
, VARCHAR2
, NVARCHAR2
, CLOB
, or NCLOB
to uppercase. Character semantics are supported for CHAR
and VARCHAR2
types. The data type of the result is the same as the data type of the expression.
LOWER
and UPPER
have the following parameter:
Parameter | Description |
---|---|
Expression1 |
An expression which is converted to lowercase (using LOWER ) or uppercase (using UPPER ). |
The LPAD
function returns Expression1
, left-padded to length n characters with the sequence of characters in Expression2
. This function is useful for formatting the output of a query.
LPAD
has the parameters:
Parameter | Description |
---|---|
Expression1 |
CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB or NCLOB operand or column to be left-padded. If Expression1 is longer than n , then LPAD returns the portion of Expression1 that fits in n . |
n |
Length of characters returned by the LPAD function. Must be a NUMBER integer or a value that can be implicitly converted to a NUMBER integer. |
Expression2 |
Sequence of characters to be left-padded in Expression1 . If you do not specify Expression2 , the default is a single blank. Operand or column can be of type CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB or NCLOB . |
If Expression1
is of type CHAR
or VARCHAR2
, the data type returned is VARCHAR2
. If Expression1
is of type NCHAR
or NVARCHAR2
, the data type returned is NVARCHAR2
. If Expression1
is a LOB, the data type returned is the same as the LOB data type provided.
The returned data type length is equal to n
if n
is a constant. Otherwise, the maximum result length of 8300 is returned.
You can specify TT_CHAR
, TT_VARCHAR
, TT_NCHAR
, and TT_NVARCHAR
for Expression1
and Expression2
. If Expression1
is of type TT_CHAR
or TT_VARCHAR
, the data type returned is TT_VARCHAR
. If Expression1
is of type TT_NCHAR
or TT_NVARCHAR
, the data type returned is TT_NVARCHAR
.
For CHAR
, VARCHAR2
, NCHAR
, NVARCHAR2
, CLOB
or NCLOB
data types:
If either Expression1
or Expression2
is NULL
, the result is NULL
. If n
is less than or equal to 0
, the result is NULL
.
For TT_CHAR
, TT_VARCHAR
, TT_NCHAR
and TT_NVARCHAR
types:
If either Expression1
or Expression2
is not NULL
and if n
is less than or equal to 0, the result is the empty string.
The following prints out the last names of the first 5 employees, left-padded with periods out to 20 characters.
Command> SELECT FIRST 5 LPAD (last_name, 20, '.') > FROM employees > ORDER BY last_name; < ................Abel > < ................Ande > < ............Atkinson > < ..............Austin > < ................Baer > 5 rows found.
Use LPAD
function to left-pad the string 'LPAD Function'
with string 'DEMO-ONLY'
plus 2 spaces. The DEMO-ONLY
string is replicated as much as it can as defined by the total characters output by the function, which is replicated three times.
Command> SELECT LPAD ('LPAD Function', 46, 'DEMO-ONLY ') FROM dual; < DEMO-ONLY DEMO-ONLY DEMO-ONLY LPAD Function > 1 row found.
Call LPAD
function with length of -1. NULL
is returned.
Command> SELECT LPAD ('abc', -1, 'a') FROM dual; < <NULL> > 1 row found.
The LTRIM
function removes from the left end of Expression1
all of the characters contained in Expression2
. TimesTen begins scanning Expression1
from its first character and removes all characters that appear in Expression2
until reaching a character not in Expression2
and returns the result.
LTRIM
has the parameters:
Parameter | Description |
---|---|
Expression1 |
The CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB or NCLOB operand or column to be trimmed. If Expression1 is a character literal, then enclose it in single quotes. |
Expression2 |
Optional expression used for trimming Expression1 . If Expression2 is a character literal, enclose it in single quotes. If you do not specify Expression2 , it defaults to a single blank. Operand or column can be of type CHAR ,VARCHAR2 , NCHAR , NVARCHAR2 , CLOB or NCLOB . |
If Expression1
is of type CHAR
or VARCHAR2
, the data type returned is VARCHAR2
. If Expression1
is of type NCHAR
or NVARCHAR2
, the data type returned is NVARCHAR2
. If Expression1
is a CLOB
or NCLOB
, the data type returned is the same as the LOB data type provided. The returned data type length is equal to the data type length of Expression1
.
If Expression1
is a data type defined with CHAR
length semantics, the returned length is expressed in CHAR
length semantics.
If either Expression1
or Expression2
is NULL
, the result is NULL
.
You can specify TT_CHAR
, TT_VARCHAR
, TT_NCHAR
, and TT_NVARCHAR
for Expression1
and Expression2
. If Expression1
is of type TT_CHAR
or TT_VARCHAR
, the data type returned is TT_VARCHAR
. If Expression1
is of type TT_NCHAR
or TT_NVARCHAR
, the data type returned is TT_NVARCHAR
.
If Expression1
is of type CHAR
or VARCHAR2
and Expression2
is of type NCHAR
or NVARCHAR2
, then Expression2
is demoted to CHAR
or VARCHAR2
before LTRIM
is invoked. The conversion of Expression2
could be lost. If the trim character of Expression2
is not in the database character set, then the query may produce unexpected results.
For CHAR
, VARCHAR2
, NCHAR
, NVARCHAR2
, CLOB
or NCLOB
types:
If all the characters in Expression1
are removed by the LTRIM
function, the result is NULL
.
For TT_CHAR
, TT_VARCHAR
, TT_NCHAR
and TT_NVARCHAR
types:
If all the characters in Expression1
are removed by the LTRIM
function, the result is the empty string.
Call the LTRIM
function to remove left-most 'x'
and 'y'
from string. LTRIM
removes individual occurrences of 'x'
and 'y'
, not pattern 'xy'
.
Command> SELECT LTRIM ('xxxyyyxyxyLTRIM Example', 'xy') FROM dual; < LTRIM Example > 1 row found.
Call the LTRIM
function to remove YYYY-MM-DD
from SYSDATE
. Call TO_CHAR
to convert SYSDATE
to VARCHAR2
.
Command> SELECT LTRIM (TO_CHAR(SYSDATE), '2007-08-21') FROM dual; < 22:54:39 > 1 row found.
Call LTRIM
to remove all characters from Expression1
. In the first example, the data type is CHAR
, so NULL
is returned. In the second example, the data type is TT_CHAR
, so the empty string is returned.
Command> CREATE TABLE ltrimtest (col1 CHAR (4), col2 TT_CHAR (4)); Command> INSERT INTO ltrimtest VALUES ('ABBB','ABBB'); 1 row inserted. Command> SELECT LTRIM (col1, 'AB') FROM ltrimtest; < <NULL> > 1 row found. Command> SELECT LTRIM (col2, 'AB') FROM ltrimtest; < > 1 row found.
Finds the largest of the values in the argument (ASCII comparison for alphabetic types). Null values are ignored. MAX
can be applied to numeric, character, and BINARY
data types. MAX
is an aggregate function and can also be an aggregate analytic function. For more details on aggregate functions, see "Aggregate functions". For more information on analytic functions, see "Analytic functions".
MAX
has the parameters:
Parameter | Description |
---|---|
Expression |
Can be any numeric data type or any nonnumeric data type that can be implicitly converted to a numeric data type. |
ALL |
Includes any duplicate rows in the argument of an aggregate function. If neither ALL nor DISTINCT is specified, ALL is assumed. |
DISTINCT |
Eliminates duplicate column values from the argument of an aggregate function. |
ROWID |
TimesTen assigns a unique ID called a rowid to each row stored in a table. The rowid value can be retrieved through the ROWID pseudocolumn. See "ROWID" for more details. |
OVER ([ AnalyticClause ]) |
If specified, indicates aggregate analytic function. For more information on analytic functions, see "Analytic functions". |
If MAX
is computed over an empty table in which GROUP BY
is not used, MAX
returns NULL
.
If MAX
is computed over an empty group or an empty grouped table (GROUP BY
is used), MAX
returns nothing.
The result data type is the same as the source.
If you do not use the AnalyticClause
in your query, then MAX
acts as an aggregate function.
Finds the smallest of the values in the argument (ASCII comparison for alphabetic types). Null values are ignored. MIN
can be applied to numeric, character, and BINARY
data types. For more details on aggregate functions, see "Aggregate functions". MIN
can also be an aggregate analytic function. For information on analytic functions, see "Analytic functions".
MIN
has the parameters:
Parameter | Description |
---|---|
Expression |
Can be any numeric data type or any nonnumeric data type that can be implicitly converted to a numeric data type. |
ALL |
Includes any duplicate rows in the argument of an aggregate function. If neither ALL nor DISTINCT is specified, ALL is assumed. |
DISTINCT |
Eliminates duplicate column values from the argument of an aggregate function. |
ROWID |
TimesTen assigns a unique ID called a rowid to each row stored in a table. The rowid value can be retrieved through the ROWID pseudocolumn. See "ROWID" for more details. |
OVER ( AnalyticClause ) |
If specified, indicates aggregate analytic function. For more information on analytic functions, see "Analytic functions". |
If the MIN
function is computed over an empty table in which GROUP BY
is not used, MIN
returns NULL
.
If the MIN
function is computed over an empty group or an empty grouped table (GROUP BY
is used), MIN
returns nothing.
The result data type is the same as the source.
If you do not use the AnalyticClause
in your query, then MIN
acts as an aggregate function.
Command> SELECT MIN(salary) "Min Salary" FROM employees; MIN SALARY < 2100 >
Show the earliest hire date:
Command> SELECT MIN(hire_date) "Earliest Hire Date" FROM employees; EARLIEST HIRE DATE < 1987-06-17 00:00:00 > 1 row found.
Returns the remainder of an INTEGER
expression divided by a second INTEGER
expression.
MOD
has the following parameters:
Parameter | Description |
---|---|
Expression1 |
An INTEGER expression. |
Expression2 |
An INTEGER expression. |
MOD
returns the remainder of Expression1
divided by Expression2
.
If Expression2
is 0
, then MOD
returns Expression1
.
If either Expression1
or Expression2
is NULL
, MOD
returns NULL
.
MOD
is treated as a binary arithmetic operation, so the return type is determined according to the rules specified in Chapter 1, "Data Types".
The MOD
function behaves differently from the classic mathematical modulus function when one of the operands is negative. The following table illustrates this difference:
M | N | Classic Modulus | MOD(M,N) |
---|---|---|---|
11 |
3 |
2 |
2 |
11 |
-3 |
-1 |
2 |
-11 |
3 |
1 |
-2 |
-11 |
-3 |
-2 |
-2 |
The following example tests whether the value of the expression m
is divisible by the value of expression n
.
SELECT m, n FROM test WHERE MOD(m, n) = 0;
The MONTHS_BETWEEN
function returns number of months between dates date1
and date2
.
MONTHS_BETWEEN
has the parameters:
Parameter | Description |
---|---|
date1 |
A datetime value or any value that can be converted to a datetime value. |
date2 |
A datetime value or any value that can be converted to a datetime value. |
Input parameters can be any combination of all supported datetime data types, excluding the TIME
or TT_TIME
data types. The supported datetime data types include DATE
, TIMESTAMP
, TT_DATE
, TT_TIMESTAMP
, ORA_DATE
, and ORA_TIMESTAMP
. For details on all datetime data types, see Chapter 1, "Data Types".
The return data type is a NUMBER
.
MONTHS_BETWEEN
returns number of months between dates date1
and date2
.
If date1
is later than date2
, the returned result is positive.
If date1
is earlier than date2
, the returned result is negative.
If date1
and date2
are both either the same day of the month or the last day of the month, the returned result is an integer. For all other cases, the returned result is a fraction based on a 31-day month that considers the difference in time components for date1
and date2
parameters.
The following examples calculate months between two given dates.
Command> SELECT MONTHS_BETWEEN(DATE '1995-02-02', DATE '1995-01-01') AS Months FROM dual; MONTHS < 1.03225806451613 > 1 row found. Command> SELECT MONTHS_BETWEEN(DATE '2010-02-02', DATE '2010-10-01') "Months" FROM dual; MONTHS < -7.96774193548387 > 1 row found.
The following command uses CAST
to explicitly convert CHAR
strings into timestamps. The first result is rounded to an integer.
Command> SELECT ROUND ( MONTHS_BETWEEN (CAST ('2010-04-15 14:13:52' AS TIMESTAMP), CAST ('2000-12-31 00:00:00' AS TIMESTAMP))), MONTHS_BETWEEN (CAST ('2010-04-15 14:13:52' AS TIMESTAMP), CAST ('2000-12-31 00:00:00' AS TIMESTAMP)) FROM dual; < 112, 111.502998805257 > 1 row found.
The NCHR
function returns the character having the specified Unicode value.
NCHR
has the parameter:
Parameter | Description |
---|---|
n |
The specified Unicode value. The character having this Unicode value is returned. The result is of type NVARCHAR2 . |
Command> SELECT NCHR(187) FROM dual; < > > 1 row found.
NLS_CHARSET_ID
returns the character set ID number corresponding to the character set name.
Note:
For a complete list of supported character sets, see "Supported character sets" in the Oracle TimesTen In-Memory Database Reference.NLS_CHARSET_ID
has the parameter:
Parameter | Description |
---|---|
String |
The input string argument is a run-time VARCHAR2 value that represents the character set. This string is case-insensitive.
If the input string corresponds to a legal TimesTen character set, the associated character set ID number is returned; otherwise, Providing |
The following example returns the character set ID number of character set US7ASCII
:
Command> select nls_charset_id('US7ASCII') from dual; < 1 > 1 row found.
Also see the example in the next section, "NLS_CHARSET_NAME", that uses the NLS_CHARSET_ID
result as input to NLS_CHARSET_NAME
.
NLS_CHARSET_NAME
returns the name of the character set corresponding to the character set ID number.
Note:
For a complete list of supported character sets, see "Supported character sets" in the Oracle TimesTen In-Memory Database Reference.NLS_CHARSET_NAME
has the parameter:
Parameter | Description |
---|---|
Number |
The number represents a character set ID. If the number does not correspond to a legal TimesTen character set ID, NULL is returned. |
The following example returns the database character set corresponding to character set ID number 1:
Command> select nls_charset_name(1) from dual; < US7ASCII > 1 row found.
The following example gets the same result, determining the name of the database character set by providing CHAR_CS
as the character set name within the NLS_CHARSET_ID
function, whose results are provided to the NLS_CHARSET_NAME
function:
SELECT NLS_CHARSET_NAME(NLS_CHARSET_ID('CHAR_CS')) FROM dual; < US7ASCII > 1 row found.
See the previous section, "NLS_CHARSET_ID", for related information.
Returns the sort key value for the given string.
NLSSORT
has the following parameters:
Parameter | Description |
---|---|
String |
Given the String , NLSSORT returns the sort key value used to sort the String . Supported data types for String are CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB , and NCLOB . |
['NLS_SORT = SortName '] |
SortName is either the linguistic sort sequence or BINARY . If you omit this parameter, then the default sort sequence for the session is used. Append to the SortName the suffix -ai for accent-insensitive sorting or -ci for case-insensitive sorting. For more information on acceptable linguistic SortName values, see "Supported linguistic sorts" in Oracle TimesTen In-Memory Database Reference. |
The returned sort key value is of type VARBINARY
.
You can create a linguistic index for linguistic comparisons.
The following example illustrates sorting and comparison operations based on a linguistic sort sequence rather than on the binary value of the string. In addition, the example shows the same results can be obtained by using the ALTER SESSION... SET NLS_SORT
statement.
Command> CREATE TABLE nsortdemo (name VARCHAR2 (15)); Command> INSERT INTO nsortdemo VALUES ('Gaardiner'); 1 row inserted. Command> INSERT INTO nsortdemo VALUES ('Gaberd'); 1 row inserted. Command> INSERT INTO nsortdemo VALUES ('Gaasten'); 1 row inserted. Command> # Perform Sort Command> SELECT * FROM nsortdemo ORDER BY name; < Gaardiner > < Gaasten > < Gaberd > 3 rows found. Command> #Use function to perform sort Command> SELECT * FROM nsortdemo ORDER BY NLSSORT (name, 'NLS_SORT = XDanish'); < Gaberd > < Gaardiner > < Gaasten > 3 rows found. Command># comparison operation Command> SELECT * FROM nsortdemo where Name > 'Gaberd'; < Gardiner > 1 row found. Command> #Use function in comparison operation Command> SELECT * FROM nsortdemo WHERE NLSSORT (name, 'NLS_SORT = XDanish') > > NLSSORT ('Gaberd', 'NLS_SORT = XDanish'); < Gaardiner > < Gaasten > 2 rows found. Command> #Use ALTER SESSION to obtain the same results Command> ALTER SESSION SET NLS_SORT = 'XDanish'; Session altered. Command> SELECT * FROM nsortdemo ORDER BY name; < Gaberd > < Gaardiner > < Gaasten > 3 rows found. Command> SELECT * FROM nsortdemo WHERE name > 'Gaberd'; < Gaardiner > < Gaasten > 2 rows found.
The following example creates a linguistic index:
Command> CREATE INDEX danishindex > ON nsortdemo (NLSSORT (name, 'NLS_SORT =XDanish')); Command> INDEXES N%; Indexes on table USER1.NSORTDEMO: DANISHINDEX: non-unique range index on columns: NLSSORT(NAME,'NLS_SORT = XDanish') 1 index found. 1 index found on 1 table.
NULLIF
compares two expressions. If the values are equal, NULLIF
returns a NULL
; otherwise, the function returns the first expression.
NULLIF
has the following parameters:
Parameter | Description |
---|---|
Expression1 |
The expression that is tested to see whether it is equal to Expression2 . You cannot specify the literal NULL for Expression1 . |
Expression2 |
The expression that is tested to see whether it is equal to Expression1 . |
If both parameters are numeric data types, Timesten determines the argument with the higher numeric precedence, implicitly converts the other argument to this data type, and returns this data type. If the parameters are not numeric data types, they must be in the same data type family.
LOB
data types are not supported in NULLIF
. The TIME
data type is only supported if both columns are of the TIME
data type.
The NULLIF
function is logically equivalent to the following CASE
expression:
CASE WHEN Expression1 = Expression2 THEN NULL ELSE Expression1 END
Note:
See "CASE expressions" for more details.The following example selects employees who have changed jobs since they were hired, which is indicated by a different job_id
in the job_history
table from the current job_id
in the employees
table. Thus, when you apply NULLIF
to the old and new job_id
entries, those that are the same returns a NULL
; those that are different indicate those employees who have changed jobs.
Command> SELECT e.last_name, NULLIF(e.job_id, j.job_id) "Old Job ID" FROM employees e, job_history j WHERE e.employee_id = j.employee_id ORDER BY last_name, "Old Job ID"; < De Haan, AD_VP > < Hartstein, MK_MAN > < Kaufling, ST_MAN > < Kochhar, AD_VP > < Kochhar, AD_VP > < Raphaely, PU_MAN > < Taylor, SA_REP > < Taylor, <NULL> > < Whalen, AD_ASST > < Whalen, <NULL> > 10 rows found.
Converts a number or expression to an INTERVAL
DAY TO SECOND
type.
NUMTODSINTERVAL
has the parameters:
Parameter | Description |
---|---|
Expression1 |
The argument can be any NUMBER value or an expression that can be implicitly converted to a NUMBER value. |
IntervalUnit |
One of the string constants: 'DAY ', 'HOUR ', 'MINUTE ', or 'SECOND '. |
Converts a number or expression to an INTERVAL YEAR TO MONTH
type.
NUMTOYMINTERVAL
has the parameters:
Parameter | Description |
---|---|
Expression1 |
The argument can be any NUMBER value or an expression that can be implicitly converted to a NUMBER value. |
IntervalUnit |
One of the string constants 'YEAR' or 'MONTH' . |
The NVL
function replaces a null value with a second value.
NVL
has the parameters:
Parameter | Description |
---|---|
Expression1 |
The expression whose values are to be tested for NULL , which can be a CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB , NCLOB , or BLOB expression. |
Expression2 |
The alternate value to use if the value of Expression1 is NULL , which can be a CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB , NCLOB , or BLOB expression. |
The data types of Expression1
and Expression2
must be compatible. If the data types are different, the data types are implicitly converted, if possible. If they cannot be implicitly converted, an error is returned.
The following describes how the implicit conversion of data types is performed:
If Expression1
is character data, then Expression2
is converted to the same data type of Expression1
and returns the result in a VARCHAR2
in the character set of Expression1
.
If Expression1
is numeric data, then TimesTen determines which expression has the highest numeric precedence and implicitly converts the other argument to that data type, which is also the data type that is returned.
If Expression1
is NULL
, the NVL
function returns Expression2
. If Expression1
is NOT NULL
, the NVL
function returns Expression1
.
The NVL
function can be used in the WHERE
or HAVING
clause of SELECT
, UPDATE
, or DELETE
statements and in the SELECT
list of a SELECT
statement.
This example checks for null values of commission_pct
and replaces them with 'Not Applicable'
for employees whose last names start with "B".
Command> SELECT last_name, NVL(TO_CHAR(commission_pct), 'Not Applicable') > FROM employees > WHERE last_name LIKE 'B%' > ORDER BY last_name; < Baer, Not Applicable > < Baida, Not Applicable > < Banda, .1 > < Bates, .15 > < Bell, Not Applicable > < Bernstein, .25 > < Bissot, Not Applicable > < Bloom, .2 > < Bull, Not Applicable > 9 rows found.
The POWER
function returns Base
raised to the Exponent
power. The Base
and Exponent
can be any numbers, but if the Base
is negative, the Exponent
must be an integer.
Parameter | Description |
---|---|
Base |
Operand or column can be any numeric type. POWER returns this value raised to Exponent power. |
Exponent |
Operand or column can be any numeric type. If Base is negative, Exponent must be an integer. |
If either Base
or Exponent
is of type BINARY_FLOAT
or BINARY_DOUBLE
, the data type returned is BINARY_DOUBLE
. If the Base
is of type NUMBER
or TT_DECIMAL
, and the Exponent
is not of type BINARY_FLOAT
or BINARY_DOUBLE
, the date type returned is NUMBER
with maximum precision and scale. If Base
is one of the TT* numeric types (TT_BIGINT
, TT_INTEGER
, TT_SMALLINT
, or TT_TINYINT
), the data type returned is BINARY_DOUBLE
.
Use the POWER
function to return the commission_pct
squared for the employee with employee_id
equal to 145.
Command> SELECT employee_id, commission_pct FROM employees WHERE employee_id = 145; < 145, .4 > 1 row found. Command> SELECT POWER (commission_pct,2) FROM employees WHERE employee_id = 145; < .16 > 1 row found.
The RANK
function is an analytic function that calculates the rank of a value in a group of values.
Parameter | Description |
---|---|
QueryPartitionClause |
For information on syntax, semantics, and restrictions, see "Analytic functions". |
OrderByClause |
For information on syntax, semantics, and restrictions, see "Analytic functions". |
The return type is NUMBER
.
Rows with equal values for the ranking criteria receive the same rank. TimesTen then adds the number of tied rows to the ties rank to calculate the next rank. Therefore, the ranks may not be consecutive numbers.
RANK
computes the rank of each row returned from a query with respect to the other rows returned by the query, based on the values of the expressions in the OrderByClause
.
Use the RANK
function to rank the first 10 employees in department 80 based on their salary and commission. Identical salary values receive the same rank and cause nonconsecutive ranks.
Command> SELECT first 10 department_id, last_name, salary, commission_pct, > RANK() OVER (PARTITION BY department_id > ORDER BY salary DESC, commission_pct) "Rank" > FROM employees WHERE department_id = 80 > ORDER BY department_id, last_name, salary, commission_pct, "Rank"; < 80, Abel, 11000, .3, 5 > < 80, Ande, 6400, .1, 31 > < 80, Banda, 6200, .1, 32 > < 80, Bates, 7300, .15, 26 > < 80, Bernstein, 9500, .25, 14 > < 80, Bloom, 10000, .2, 9 > < 80, Cambrault, 7500, .2, 23 > < 80, Cambrault, 11000, .3, 5 < 80, Doran, 7500, .3, 24 > < 80, Errazuriz, 12000, .3, 3 > 10 rows found.
REPLACE
substitutes a sequence of characters in a given string with another set of characters or removes the string entirely.
Parameter | Description |
---|---|
String |
Source string containing the substring to replace. |
SearchString |
String of characters to be replaced in the original string. If SearchString is NULL , the original String is returned without any modification. |
ReplacementString |
String of characters that are used to replace all occurrences of the search string in the original string. If ReplacementString is omitted or NULL , all occurrences of SearchString are removed from the source String . |
REPLACE
returns a string where every occurrence of the SearchString
is replaced with ReplacementString
in the source String
.
String
, SearchString
and ReplacementString
can be any of the following data types: CHAR
, VARCHAR2
, NCHAR
, NVARCHAR2
, CLOB
, or NCLOB
. Both TimesTen and Oracle Database data types are supported. All non-character data types, except for BLOB
, are implicitly converted to a string data type.
If String
is a CHAR
or VARCHAR2
, the returned string is of data type VARCHAR2
. If String
is an NCHAR
or NVARCHAR2
, the returned string is of data type NVARCHAR2
. For CLOB
or NCLOB
data types, the data type returned is the same as the data type provided in String
. The character set is the same as the source String
.
If the returned string length is zero, NULL
is returned for Oracle Database data types and a zero length string is returned for TimesTen data types. See Chapter 1, "Data Types" for details on all data types.
The following prints out all locations in Canada, replacing the country code of CA with Canada for easier readability.
Command> SELECT location_id, street_address, > city, state_province, postal_code, > REPLACE(country_id, 'CA', 'Canada') > FROM LOCATIONS > WHERE country_id LIKE 'CA'; < 1800, 147 Spadina Ave, Toronto, Ontario, M5V 2L7, Canada > < 1900, 6092 Boxwood St, Whitehorse, Yukon, YSW 9T2, Canada > 2 rows found.
Returns date rounded to the unit specified by the format model fmt
. The value returned is of type DATE
. If you do not specify fmt
, then date
is rounded to the nearest day.
ROUND (
Date
)
has the parameters:
Parameter | Description |
---|---|
Date |
The date that is rounded. Must resolve to a date value.
If you do not specify |
[, Fmt ] |
The format model rounding unit. Specify either a constant or a parameter for fmt . |
Date can be of type DATE
or TIMESTAMP
. The data type returned is DATE
.
Data types TT_DATE
and TT_TIMESTAMP
are not supported.
For the supported format models to use in fmt
, see "Format model for ROUND and TRUNC date functions".
Round Date
to the first day of the following year by specifying 'YEAR'
as the format model:
Command> SELECT ROUND (DATE '2007-08-25','YEAR') FROM dual; < 2008-01-01 00:00:00 > 1 row found.
Omit Fmt
. Specify Date
as type TIMESTAMP
with a time of 13:00:00
. Date
is rounded to nearest day:
Command> SELECT ROUND (TIMESTAMP '2007-08-16 13:00:00') FROM dual; < 2007-08-17 00:00:00 > 1 row found.
The ROUND
function returns Expression1
rounded to Expression2
places to the right of the decimal point.
ROUND
has the parameters:
Parameter | Description |
---|---|
Expression1 |
Operand or column can be any numeric type. |
Expression2 |
Operand or column that indicates how many places to round. Can be negative to round off digits left of the decimal point. If you omit Expression2 , then Expression1 is rounded to 0 places. Must be an integer. |
If you omit Expression2
, the data type returned is the same as the numeric data type of Expression1
, unless Expression1
is of type TT_DECIMAL
. If Expression1
is of type TT_DECIMAL
and you omit Expression2,
the data type returned is NUMBER
with maximum precision and scale.
If you specify Expression2
, the data type returned is NUMBER
with maximum precision and scale.
If Expression1
is of type BINARY_FLOAT
or BINARY_DOUBLE
, the value of Expression1
is rounded to the nearest even value. Otherwise, the value of Expression1
is rounded away from 0 (for example, to x
+1
when x
.5
is positive and to x
-1
when x
.5 is negative).
Round a number two places to the right of the decimal point.
Command> SELECT ROUND (15.5555,2) FROM dual; < 15.56 > 1 row found.
Round a number to the left of the decimal point by specifying a negative number for Expression2
.
Command> SELECT ROUND (15.5555,-1) FROM dual; < 20 > 1 row found.
Round a floating point number. Floating point numbers are rounded to nearest even value. Contrast this to rounding an expression of type NUMBER
where the value is rounded up (for positive values).
Command> SELECT ROUND (1.5f), ROUND (2.5f) FROM dual; < 2.00000000000000, 2.00000000000000 > 1 row found. Command> SELECT ROUND (1.5), ROUND (2.5) FROM dual; < 2, 3 > 1 row found.
The ROW_NUMBER
function is an analytic function that assigns a unique number to each row to which it is applied (either each row in a partition or each row returned by the query), in the ordered sequence of rows specified in OrderByClause
, beginning with 1.
Parameter | Description |
---|---|
QueryPartitionClause |
For information on syntax, semantics, and restrictions, see "Analytic functions". |
OrderByClause |
For information on syntax, semantics, and restrictions, see "Analytic functions". |
ROWNUM
pseudo column returns a number indicating the order in which TimesTen selects a row from a table or a set of joined rows. In contrast, the analytic function, ROW_NUMBER
, gives superior support in ordering the results of a query before assigning the number.
By nesting a subquery, using ROW_NUMBER
, inside a query that retrieves the ROW_NUMBER
values for a specified range, you can find a precise subset or rows from the results of the inner query. For consistent results, the query must ensure a deterministic sort order.
The return data type is NUMBER
.
Use ROW_NUMBER
to return the three highest paid employees in each department. Fewer then three rows are returned for departments with fewer than three employees.
Command> SELECT FIRST 10 department_id, first_name, last_name, salary > FROM > (SELECT department_id, first_name, last_name, salary, ROW_NUMBER() > OVER (PARTITION BY department_id ORDER BY salary desc) rn > FROM employees ) > WHERE rn <= 3 > ORDER BY department_id, salary DESC, last_name; < 10, Jennifer, Whalen, 4400 > < 20, Michael, Hartstein, 13000 > < 20, Pat, Fay, 6000 > < 30, Den, Raphaely, 11000 > < 30, Alexander, Khoo, 3100 > < 30, Shelli, Baida, 2900 > < 40, Susan, Mavris, 6500 > < 50, Adam, Fripp, 8200 > < 50, Matthew, Weiss, 8000 > < 50, Payam, Kaufling, 7900 > 10 rows found.
The RPAD
function returns Expression1
, right-padded to length n
characters with Expression2
, replicated as many times as necessary. This function is useful for formatting the output of a query.
RPAD
has the parameters:
Parameter | Description |
---|---|
Expression1 |
CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB or NCLOB operand or column to be right-padded. If Expression1 is longer than n , then RPAD returns the portion of Expression1 that fits in n . |
n |
Length of characters returned by RPAD function. Must be a NUMBER integer or a value that can be implicitly converted to a NUMBER integer. |
Expression2 |
CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB or NCLOB operand or column to be right-padded to Expression1 . If you do not specify Expression2 , the default is a single blank. |
If Expression1
is of type CHAR
or VARCHAR2
, the data type returned is VARCHAR2
. If Expression1
is of type NCHAR
or NVARCHAR2
, the data type returned is NVARCHAR2
. If Expression1
is a LOB, the data type returned is the same as the LOB data type provided.
The returned data type length is equal to n
if n
is a constant. Otherwise, the maximum result length of 8300 is returned.
You can specify TT_CHAR
, TT_VARCHAR
, TT_NCHAR
, and TT_NVARCHAR
for Expression1
and Expression2
. If Expression1
is of type TT_CHAR
or TT_VARCHAR
, the data type returned is TT_VARCHAR
. If Expression1
is of type TT_NCHAR
or TT_NVARCHAR
, the data type returned is TT_NVARCHAR
.
For CHAR
, VARCHAR2
, NCHAR
, NVARCHAR2
, CLOB
or NCLOB
data types:
If either Expression1
or Expression2
is NULL
, the result is NULL
. If n
is less than or equal to 0
, the result is NULL
.
For TT_CHAR
, TT_VARCHAR
, TT_NCHAR
and TT_NVARCHAR
types:
If either Expression1
or Expression2
is not NULL
and if n
is less than or equal to 0
, the result is the empty string.
Concatenate first_name
and last_name
from the employees
table. Call the RPAD
function to return first_name
right-padded to length 12 with spaces and call RPAD
a second time to return last_name
right-padded to length 12 with spaces. Select first five rows.
Command> SELECT FIRST 5 CONCAT (RPAD (first_name,12), > RPAD (last_name,12)) FROM employees > ORDER BY first_name, last_name; < Adam Fripp > < Alana Walsh > < Alberto Errazuriz > < Alexander Hunold > < Alexander Khoo > 5 rows found.
Call the RPAD
function to return last_name
right-padded to length 20 characters with the dot ('.
') character. Use the employees
table and select first five rows.
Command> SELECT FIRST 5 RPAD (last_name,20,'.') FROM employees > ORDER BY last_name; < Abel................ > < Ande................ > < Atkinson............ > < Austin.............. > < Baer................ > 5 rows found.
The RTRIM
function removes from the right end of Expression1
all of the characters contained in Expression2
. TimesTen scans Expression1
backward from its last character and removes all characters that appear in Expression2
until reaching a character not in Expression2
and then returns the result.
Parameter | Description |
---|---|
Expression1 |
The CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB or NCLOB operand or column to be trimmed. If Expression1 is a character literal, then enclose it in quotes. |
Expression2 |
Optional expression used for trimming Expression1 . If Expression2 is a character literal, enclose it in single quotes. If you do not specify Expression2 , it defaults to a single blank. Operand or column can be of type CHAR ,VARCHAR2 , NCHAR , NVARCHAR2 , CLOB or NCLOB . |
If Expression1
is of type CHAR
or VARCHAR2
, the data type returned is VARCHAR2
. If Expression1
is of type NCHAR
or NVARCHAR2
, the data type returned is NVARCHAR2
. If Expression1
is a CLOB
or NCLOB
, the data type returned is the same as the LOB data type provided. The returned data type length is equal to the data type length of Expression1
.
If Expression1
is a data type defined with CHAR
length semantics, the returned length is expressed in CHAR
length semantics.
If either Expression1
or Expression2
is NULL
, the result is NULL
.
You can specify TT_CHAR
, TT_VARCHAR
, TT_NCHAR
, and TT_NVARCHAR
for Expression1
and Expression2
. If Expression1
is of type TT_CHAR
or TT_VARCHAR
, the data type returned is TT_VARCHAR
. If Expression1
is of type TT_NCHAR
or TT_NVARCHAR
, the data type returned is TT_NVARCHAR
.
If Expression1
is of type CHAR
or VARCHAR2
and Expression2
is of type NCHAR
or NVARCHAR2
, then Expression2
is demoted to CHAR
or VARCHAR2
before RTRIM
is invoked. The conversion of Expression2
could be lost. If the trim character of Expression2
is not in the database character set, then the query may produce unexpected results.
For CHAR
, VARCHAR2
, NCHAR
, NVARCHAR2
, CLOB
and NCLOB
types:
If all the characters in Expression1
are removed by the RTRIM
function, the result is NULL
.
For TT_CHAR
, TT_VARCHAR
, TT_NCHAR
and TT_NVARCHAR
types:
If all the characters in Expression1
are removed by the RTRIM
function, the result is the empty string.
The following example trims the trailing spaces from col1
in table rtrimtest
.
Command> CREATE TABLE rtrimtest (col1 VARCHAR2 (25)); Command> INSERT INTO rtrimtest VALUES ('abc '); 1 row inserted. Command> SELECT * FROM rtrimtest; < abc > 1 row found. Command> SELECT RTRIM (col1) FROM rtrimtest; < abc > 1 row found.
Call the RTRIM
function to remove right-most 'x'
and 'y'
from string. RTRIM
removes individual occurrences of 'x'
and 'y'
, not pattern 'xy'
.
Command> SELECT RTRIM ('RTRIM Examplexxxyyyxyxy', 'xy') FROM dual; < RTRIM Example > 1 row found.
Call RTRIM
to remove all characters from Expression1
. In the first example, the data type is CHAR
, so NULL
is returned. In the second example, the data type is TT_CHAR
, so the empty string is returned.
Command> CREATE TABLE rtrimtest (col1 CHAR (4), col2 TT_CHAR (4)); Command> INSERT INTO rtrimtest VALUES ('BBBA', 'BBBA'); 1 row inserted. Command> SELECT RTRIM (col1, 'AB') FROM rtrimtest; < <NULL> > 1 row found. Command> SELECT RTRIM (col2, 'AB') FROM rtrimtest; < > 1 row found.
The SIGN
function returns the sign of Expression
.
SIGN
has the parameter:
Parameter | Description |
---|---|
Expression |
Operand or column can be any numeric data type. |
If Expression
is of type NUMBER
or TT_DECIMAL
, the data type returned is NUMBER
with maximum precision and scale. Otherwise, the data type returned is TT_INTEGER
.
For numeric types that are not binary floating-point numbers, the sign is:
-1 if the value of Expression
is <0
0 if the value of Expression
is = 0
1 if the value of Expression
is > 0
For binary floating-point numbers (BINARY_FLOAT
and BINARY_DOUBLE
), this function returns the sign bit of the number. The sign bit is:
-1 if the value of Expression
is <0
+1
if the value of Expression
is >= 0
or the value of Expression
is equal to NaN
These examples illustrate use of the SIGN
function with different data types. Table signex
has been created and the columns have been defined with different data types. First, describe the table signex
to see the data types of the columns. Then select each column to retrieve values for that column. Use the SIGN
function to return the sign for the column.
Command> DESCRIBE signex; Table SAMPLEUSER.SIGNEX: Columns: COL1 TT_INTEGER COL2 TT_BIGINT COL3 BINARY_FLOAT COL4 NUMBER (3,2) 1 table found. (primary key columns are indicated with *) Command> SELECT col1 FROM signex; < 10 > < -10 > < 0 > 3 rows found. Command> SELECT SIGN (col1) FROM signex; < 1 > < -1 > < 0 > 3 rows found. Command> SELECT col2 FROM signex; < 0 > < -3 > < 0 > 3 rows found. Command> SELECT SIGN (col2) FROM signex; < 0 > < -1 > < 0 > 3 rows found. Command> SELECT col3 FROM signex; < 3.500000 > < -3.560000 > < NAN > 3 rows found. Command> SELECT SIGN (col3) FROM signex; < 1 > < -1 > < 1 > 3 rows found. Command> SELECT col4 FROM signex; < 2.2 > < -2.2 > < 0 > 3 rows found. Command> SELECT SIGN (col4) FROM signex; < 1 > < -1 > < 0 > 3 rows found.
The SOUNDEX
function determines a phonetic signature for a string and allows comparisons of strings based on phonetic similarity. SOUNDEX
lets you compare words that are spelled differently, but sound alike in English.
Parameter | Description |
---|---|
InputString |
Valid types are CHAR , VARCHAR2 , NCHAR and NVARCHAR2 with both ORA and TT variants and CLOB and NCLOB . If the data type is CLOB or NCLOB , TimesTen performs implicit conversion before returning the result. |
Converts an alpha-numeric string into a 4 character code, beginning with the first letter encountered in the string, followed by three numbers.
The phonetic representation is defined in The Art of Computer Programming, Volume 3: Sorting and Searching, by Donald E. Knuth, as follows:
Retain the first letter of the string and drop all other occurrences of the following letters: A, E, I, O, U. The treatment of the letters is case insensitive.
Drop all occurrences of H, W, and Y.
Assign numbers to the remaining letters (after the first) as follows:
B, F, P, V = 1 C, G, J, K, Q, S, X, Z = 2 D, T = 3 L = 4 M, N = 5 R = 6
If two or more letters with the same number were adjacent in the original name (before step 1), omit all but the first.
Return the first four characters of the result (padded with '0' if the result has less than four characters).
The function returns NULL
if no soundex
code could be generated for the InputString
. For example, NULL
is returned when the InputString
contains no English letters.
The input to output type mapping is:
Input Type | Output Type |
---|---|
VARCHAR2 (x ), CHAR , CLOB |
VARCHAR2(4) |
TT_CHAR (x ), TT_VARCHAR (x ) |
TT_VARCHAR(4) |
NVARCHAR2 (x ), NCHAR (x ), NCLOB |
NVARCHAR2(4) |
TT_NCHAR (x ), TT_NVARCHAR (x ) |
TT_NVARCHAR(4) |
Use SOUNDEX
function to return the phonetic signature for employees with last name equal to 'Taylor'.
Command> SELECT last_name, first_name, SOUNDEX (last_name) > FROM employees where last_name = 'Taylor'; < Taylor, Jonathon, T460 > < Taylor, Winston, T460 > 2 rows found.
Invoke the function again to return the phonetic signature for the string 'Tailor'. Invoke the function a third time to return the last name and first name of each employee whose last name is phonetically similar to the string 'Tailor'.
Command> SELECT SOUNDEX ('Tailor') FROM dual; < T460 > 1 row found. Command> SELECT last_name, first_name FROM employees WHERE SOUNDEX (last_name) = > SOUNDEX ('Tailor'); < Taylor, Jonathon > < Taylor, Winston > 2 rows found.
The SQRT
function returns the square root of Expression
.
SQRT
has the parameter:
Parameter | Description |
---|---|
Expression |
Operand or column can be any numeric data type. |
If Expression
is of type NUMBER
or TT_DECIMAL
, the data type returned is NUMBER
with maximum precision and scale. If Expression
is of type BINARY_FLOAT
, the data type returned is BINARY_FLOAT
. Otherwise, the data type returned is BINARY_DOUBLE
.
If Expression
is of type NUMBER
or TT_DECIMAL
, the value of Expression
cannot be negative.
If Expression
resolves to a binary floating-point number (BINARY_FLOAT
or BINARY_DOUBLE
):
If the value of the Expression
is > = 0
, the result is positive.
If the value of the Expression
is = -0
, the result is -0
.
If the value of the Expression
is < 0
, the result is NaN
.
Returns a string that represents a substring of a source string. The returned substring is of a specified number of characters, beginning from a designated starting point, relative to either the beginning or end of the string.
SUBSTR
has the parameters:
Parameter | Description |
---|---|
Source |
The string for which this function returns a substring. Value can be any supported character data types including CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB , or NCLOB data types. Both TimesTen and Oracle Database data types are supported.
If |
m |
The position at which to begin the substring. If m is positive, the first character of the returned string is m characters from the beginning of the string specified in char . Otherwise it is m characters from the end of the string. If ABS (m ) is bigger than the length of the character string, a null value is returned. |
n |
The number of characters to be included in the substring. If n is omitted, all characters to the end of the string specified in char are returned. If n is less than 1 or if char , m or n is NULL , NULL is returned. |
SUBSTR
calculates lengths using characters as defined by character set. SUBSTRB
uses bytes instead of characters. SUBSTR4
uses UCS4 code points.
In the first five rows of employees
, select the first three characters of last_name
:
SELECT FIRST 5 SUBSTR(last_name,1,3) FROM employees; < Kin > < Koc > < De > < Hun > < Ern > 5 rows found.
In the first five rows of employees
, select the last five characters of last_name
:
SELECT FIRST 5 SUBSTR(last_name,-5,5) FROM employees; < <NULL> > < chhar > < Haan > < unold > < Ernst > 5 rows found.
Finds the total of all values in the argument. Null values are ignored. SUM
is an aggregate function. SUM
can also be an aggregate analytic function. For more details on aggregate functions, see "Aggregate functions". For more information on analytic functions, see "Analytic functions".
SUM
has the parameters:
Parameter | Description |
---|---|
Expression |
Can be any numeric data type or any nonnumeric data type that can be implicitly converted to a numeric data type. |
ALL |
Includes any duplicate rows in the argument of an aggregate function. If neither ALL nor DISTINCT is specified, ALL is assumed. |
DISTINCT |
Eliminates duplicate column values from the argument of an aggregate function. |
OVER ([ AnalyticClause ]) |
If specified, indicates aggregate analytic function. For more information on analytic functions, see "Analytic functions". |
If the SUM
function is computed over an empty table in which GROUP BY
is not used, SUM
returns NULL
.
If the SUM
function is computed over an empty group or an empty grouped table (GROUP BY
is used), SUM
returns nothing.
If the source is TT_TINYINT
, TT_SMALLINT
, or TT_INTEGER
, the result data type is TT_INTEGER
.
If the source is NUMBER
, then the result data type is NUMBER
with undefined scale and precision.
If the source is TT_DECIMAL
, then the result data type is TT_DECIMAL
with maximum precision.
For all other data types, the result data type is the same as the source.
If you do not use the AnalyticClause
in your query, then SUM
acts as an aggregate function.
If you specify DISTINCT
and the AnalyticClause
, then you can only specify the QueryPartitionClause
. The OrderByClause
and WindowingClause
are not allowed.
Returns information about the current session.
The data type of the return value is VARCHAR2
.
SYS_CONTEXT
has the parameters:
Parameter | Description |
---|---|
namespace |
Value: USERENV
Other values result in a return of |
parameter |
Supported values:
|
length |
Length in bytes, from 1 to 4000. |
These are descriptions of the supported values for parameter
:
Parameter | Description |
---|---|
AUTHENTICATION_METHOD |
Returns the method of authentication for these types of users:
|
CURRENT_USER |
The name of the database user whose privileges are currently active. This may change during the duration of a session to reflect the owner of any active definer's rights object. When no definer's rights object is active, CURRENT_USER returns the same value as SESSION_USER . When used directly in the body of a view definition, this returns the user that is executing the cursor that is using the view. It does not respect views used in the cursor as being definer's rights. |
CURRENT_USERID |
The identifier of the database user whose privileges are currently active. |
IDENTIFICATION_TYPE |
Returns the way the user was created in the database. Specifically, it reflects the IDENTIFIED clause in the CREATE /ALTER USER syntax. In the list that follows, the syntax used during user creation is followed by the identification type returned:
|
LANG |
The ISO abbreviation for the language name, a shorter form than the existing 'LANGUAGE' parameter. |
LANGUAGE |
The language and territory currently used by the session, along with the database character set, in this form:
|
NLS_SORT |
Binary or linguistic sort. |
SESSION_USER |
The name of the database user at logon. This value remains the same throughout the duration of the session. |
SESSION_USERID |
The identifier of the database user at logon. |
SID |
The connection ID of the current connection. |
Returns the date in the format YYYY-MM-DD HH:MI:SS
. The date represents the local current date and time, which is determined by the system on which the statement is executed.
If you are using TimesTen type mode, for information on SYSDATE
, see the Oracle TimesTen In-Memory Database Release 6.0.3 documentation.
SYSDATE
and GETDATE
perform identically. SYSDATE
is compatible with Oracle Database syntax. GETDATE
is compatible with Microsoft SQL Server syntax.
SYSDATE
and GETDATE
have no arguments, and return a DATE
value.
The SYSDATE
or GETDATE
value is only retrieved during execution.
Any required changes to the date (to incorporate a different time zone or Daylight Savings Time, for example) must occur at the system level. The date cannot be altered using SYSDATE
or GETDATE
.
The SYSDATE
and GETDATE
functions return the DATE
data type. The DATE
format is '
YYYY-MM-DD HH:MI:SS
'
.
SYSDATE
and GETDATE
are built-in functions and can be used anywhere a date expression may be used. They can be used in a INSERT...SELECT
projection list, a WHERE
clause or to insert values. They cannot be used with a SUM
or AVG
aggregate (operands must be numeric) or with a COUNT
aggregate (column names are expected).
SYSDATE
and GETDATE
return the same DATE
value in a single SQL statement context.
The literals TT_SYSDATE
and ORA_SYSDATE
are supported. TT_SYSDATE
returns the TT_TIMESTAMP
data type. ORA_SYSDATE
returns the DATE
data type.
In this example, invoking SYSDATE
returns the same date and time for all rows in the table:
Command> SELECT SYSDATE FROM dual; < 2006-09-03 10:33:43 > 1 row found.
This example invokes SYSDATE
to insert the current data and time into column datecol
:
Command> CREATE TABLE t (datecol DATE); Command> INSERT INTO t VALUES (SYSDATE); 1 row inserted. Command> SELECT * FROM t; < 2006-09-03 10:35:50 > 1 row found.
In this example, GETDATE
inserts the same date value for each new row in the table, even if the query takes several seconds.
INSERT INTO t1 SELECT GETDATE(), col1 FROM t2 WHERE ...;
TO_CHAR
is used with SYSDATE
to return the date from table dual
:
Command> SELECT TO_CHAR (SYSDATE) FROM dual; < 2006-09-03 10:56:35 > 1 row found.
This example invokes TT_SYSDATE
to return the TT_TIMESTAMP
data type and then invokes ORA_SYSDATE
to return the DATE
data type:
Command> SELECT tt_sysdate FROM dual; < 2006-10-31 20:02:19.440611 > 1 row found. Command> SELECT ora_sysdate FROM dual; < 2006-10-31 20:02:30 > 1 row found.
The TIMESTAMPADD
function adds a specified number of intervals to a timestamp and returns the modified timestamp.
TIMESTAMPADD
has the parameters:
Parameter | Description |
---|---|
Interval |
Specified interval. Must be expressed as literal. Valid values are listed in the description section. |
IntegerExpression |
Expression that evaluates to TT_BIGINT . |
TimestampExpression |
Datetime expressions. Valid data types are ORA_DATE , ORA_ TIMESTAMP , TT_DATE , and TT_TIMESTAMP . (The alias DATE and TIMESTAMP data types are also valid). TT_TIME is not supported. |
Valid values for Interval
are:
SQL_TSI_FRAC_SECOND
SQL_TSI_SECOND
SQL_TSI_MINUTE
SQL_TSI_HOUR
SQL_TSI_DAY
SQL_TSI_WEEK
SQL_TSI_MONTH
SQL_TSI_QUARTER
SQL_TSI_YEAR
SQL_TSI_FRAC_SECOND
is expressed in billionths of a second.
The return type is the same as the original data type. For example, if your expression is of type TIMESTAMP
, then the resulting data type is TIMESTAMP
. Only positive timestamp expressions (0001-01-01) are allowed both in the query and the result. For TT_DATE
and TT_TIMESTAMP
, because the starting range for these data types is 1753-01-01, the timestamp expression must be equal to or greater than this date.
If IntegerExpression
or TimestampExpression
is NULL
, then the result is NULL
.
The function computes the total time interval as a product of the IntegerExpression
and the interval and adds it to the specified TimestampExpression
. Adding a year advances the timestamp by 12 months and adding a week advances the timestamp by seven days. If the IntegerExpression
is negative, the specified interval is subtracted from the TimestampExpression
.
There is a possibility of precision loss depending on your use of the specified interval and timestamp expression. For example, if your interval is SQL_TSI_
HOUR
, and you specify 2 for IntegerExpression
and TT_DATE
for TimestampExpression
, TimesTen treats the two hours as zero days and returns the sum of the original date plus zero days resulting in some loss of precision. If however, your IntegerExpression
is 48, TimesTen treats the 48 hours as two days and returns the sum of the original date plus two days. In this case, there is no loss of precision.
If the addition of the timestamp results in an overflow of the specified component (such as more than 60 seconds, or more than 24 hours, or more than 12 months), then the overflow is carried over to the next component. For example, if the seconds component overflows, then the minutes component is advanced.
Use the TIMESTAMPADD
function to add 3 months to timestamp '2009-11-30 10:00:00'. TimesTen increments the year and adjusts the day component to accommodate the 28 days in the month of February.
Command> SELECT TIMESTAMPADD (SQL_TSI_MONTH, 3, TIMESTAMP '2010-11-30 10:00:00') > FROM dual; < 2011-02-28 10:00:00 > 1 row found.
Use the TIMESTAMPADD
function to add 1 second to timestamp '2010-12-31 23:59:59'. TimesTen propagates the overflow through all components of the timestamp and advances the components appropriately.
Command> SELECT TIMESTAMPADD (SQL_TSI_SECOND, 1, TIMESTAMP '2010-12-31 23:59:59') > FROM dual; < 2011-01-01 00:00:00 > 1 row found.
The TIMESTAMPDIFF
function returns the total number of specified intervals between two timestamps.
TIMESTAMPDIFF
has the parameters:
Parameter | Description |
---|---|
Interval |
Specified interval. Must be expressed as literal. Valid values are listed in the description section. |
TimestampExpression 1 |
Datetime expressions. Valid data types are ORA_DATE , ORA_ TIMESTAMP , TT_DATE , and TT_TIMESTAMP . (The alias DATE and TIMESTAMP data types are also valid.) TT_TIME is not supported. |
TimestampExpression 2 |
Datetime expressions. Valid data types are ORA_DATE , ORA_ TIMESTAMP , TT_DATE , and TT_TIMESTAMP . (The alias DATE and TIMESTAMP data types are also valid.) TT_TIME is not supported. |
Valid values for Interval
are:
SQL_TSI_FRAC_SECOND
SQL_TSI_SECOND
SQL_TSI_MINUTE
SQL_TSI_HOUR
SQL_TSI_DAY
SQL_TSI_WEEK
SQL_TSI_MONTH
SQL_TSI_QUARTER
SQL_TSI_YEAR
SQL_TSI_FRAC_SECOND
is expressed in billionths of a second.
Interval
determines the units in which the difference in timestamps is returned. For example, if you specify SQL_TSI_YEAR
, the difference in timestamps is returned in years.
TimesTen returns the result as the difference between TimestampExpression2
minus (-) TimestampExpression1
. The return type is TT_BIGINT
.
Only positive timestamp expressions (0001-01-01) are allowed. For TT_DATE
and TT_TIMESTAMP
, because the starting range for these data types is 1753-01-01, the timestamp expression must be equal to or greater than this date.
If TimestampExpression1
or TimestampExpression2
is NULL
, then the result is NULL
.
If either timestamp expression is a date value and Interval
specifies fractional seconds, seconds, minutes, or hours, the time portion of the timestamp is set to 0 before TimesTen calculates the difference between the timestamps.
The function first expresses each of the timestamps in units of the specified Interval
by converting the higher order interval type to the specified interval type. For example, TimesTen converts years to months if the specified interval is months. Thus, one year is 12 months, one week is seven days, and so on. To find the number of days between two timestamps, the exact number of days is computed. Since months vary in the number of days, TimesTen does not make an assumption about the number of days in a month.
The function increments the specified interval whenever fractional intervals cross an interval boundary. For example, the difference in years between 2009-12-31 and 2010-01-01 is one year because the fractional year represents a crossing from one year to the next (2009 to 2010). However, the difference between 2010-01-01 and 2010-12-31 is zero years because the fractional interval does not cross a boundary. It falls within the year 2010.
The function calculates the difference in weeks by first calculating the difference in days and then divides the result by seven before rounding. TimesTen assumes a week starts on a Sunday. Therefore the difference in weeks between 2010-10-21 (a Thursday) and 2010-10-25 (the following Monday) results in a value of one week. The difference in the same dates, if Tuesday denoted the start of the week, would result in zero weeks.
Use the TIMESTAMPDIFF
function to calculate the difference in days between dates 2008-02-01 and 2008-03-01. Because 2008 is a leap year, the result is 29 days. The calculation is precise with no assumption of a 30-day month.
Command> SELECT TIMESTAMPDIFF (SQL_TSI_DAY, DATE '2008-02-01', > DATE '2008-03-01') FROM dual; < 29 > 1 row found.
Use the TIMESTAMPDIFF
function to calculate the difference in months between dates 2009-02-01 and 2009-03-01. Because there is a crossing of the interval month boundary, the function returns 1. In the second example, because days is specified for the interval, the result is 28.
Command> SELECT TIMESTAMPDIFF (SQL_TSI_MONTH, DATE '2009-02-01', > DATE '2009-03-01') FROM dual; < 1 > 1 row found. Command> SELECT TIMESTAMPDIFF (SQL_TSI_DAY, DATE '2009-02-01', > DATE '2009-03-01') FROM dual; < 28 > 1 row found.
Use the TIMESTAMPDIFF
function to calculate the difference in months between dates 2009-02-01 and 2009-02-29. Because there is not a crossing of the interval month boundary, the function returns 0.
Command> SELECT TIMESTAMPDIFF (SQL_TSI_MONTH, DATE '2009-02-01', > DATE '2009-02-28') FROM dual; < 0 > 1 row found.
Use the TIMESTAMPDIFF
function to illustrate the time difference in fractional seconds between mixed types. The time difference of one hour is returned in nanoseconds (unit for fractional seconds). The time element of the data type is set to 00:00:00.
Command> SELECT TIMESTAMPDIFF (SQL_TSI_FRAC_SECOND, > TT_TIMESTAMP '2009-12-31 01:00:00.00', DATE '2009-12-31') FROM dual; < -3600000000000 > 1 row found.
The TO_BLOB
function converts VARBINARY
or BINARY
to a BLOB
:
TO_BLOB
has the parameters:
Parameter | Description |
---|---|
ValidDataType |
A value that is of VARBINARY or BINARY data type. |
The following example creates a table with a BINARY
and a VARBINARY
columns. The TO_BLOB
function is used on the values of these columns to convert the BINARY
and VARBINARY
data to a BLOB
.
Command> CREATE TABLE bvar > (col1 BINARY (10), col2 VARBINARY (10)); Command> INSERT INTO bvar (col1, col2) > VALUES (0x4D7953514C, 0x39274D); 1 row inserted. Command> SELECT * FROM bvar; < 4D7953514C0000000000, 39274D > 1 row found. Command> SELECT TO_BLOB(col1), TO_BLOB(col2) > FROM bvar; < 4D7953514C0000000000, 39274D > 1 row found.
The TO_CHAR
function converts a DATE
, TIMESTAMP
or numeric input value to a VARCHAR2
.
If you are using TimesTen type mode, for information on the TO_CHAR
function, see the Oracle TimesTen In-Memory Database Release 6.0.3 documentation.
TO_CHAR
has the parameters:
Parameter | Description |
---|---|
Expression1 |
A DATE , TIMESTAMP , CLOB , NCLOB , or numeric expression. |
Expression2 |
The format string. If omitted, TimesTen uses the default date format (YYYY-MM-DD ). |
Expression3 |
A CHAR or VARCHAR2 expression to specify the NLS parameter, which is currently ignored. |
TO_CHAR
supports different datetime format models depending on the data type specified for the expression. For information on the datetime format model used for TO_CHAR
of data type DATE
or TIMESTAMP
, see "Datetime format models". For information on the datetime format model used for TO_CHAR
of data type TT_DATE
or TT_TIMESTAMP
, see "Format model for ROUND and TRUNC date functions".
TO_CHAR
supports different number format models depending on the numeric data type specified for the expression. For information on the number format model used for TO_CHAR
of data type NUMBER
or ORA_FLOAT
, see "Number format models". For information on the number format model used for TO_CHAR
of all other numeric data types, see "Format model for ROUND and TRUNC date functions".
SELECT FIRST 5 first_name, TO_CHAR (hire_date, 'MONTH DD, YYYY'), TO_CHAR (salary, '$999999.99') FROM employees; < Steven, JUNE 17, 1987, $24000.00 > < Neena, SEPTEMBER 21, 1989, $17000.00 > < Lex, JANUARY 13, 1993, $17000.00 > < Alexander, JANUARY 03, 1990, $9000.00 > < Bruce, MAY 21, 1991, $6000.00 > 5 rows found. SELECT TO_CHAR(-0.12,'$B99.9999') FROM dual; < -$.1200 > 1 row found. SELECT TO_CHAR(-12, 'B99999PR') FROM dual; < 12 > 1 row found. SELECT TO_CHAR(-12,'FM99999') FROM dual; < -12 > 1 row found. SELECT TO_CHAR(1234.1,'9,999.999') FROM dual; < 1,234.100 > 1 row found.
The TO_CLOB
function converts one of the following values to a CLOB
:
Character value contained in one of the following data types: CHAR
, VARCHAR2
, NVARCHAR2
, TT_VARCHAR
, TT_NVARCHAR
, or NCLOB
Datetime value contained in a DATE
or TIMESTAMP
data type
Number value contained in a NUMBER
, BINARY_FLOAT
, or BINARY_DOUBLE
data type
TO_CLOB
has the parameters:
Parameter | Description |
---|---|
ValidDataType |
A value of one of the valid data types mentioned above. |
The TO_CLOB
function will not operate on values contained in INTERVAL
or TIMESTAMP with TIMEZONE
data types.
The following example uses the TO_CLOB
function to convert a string.
Command> DESCRIBE clob_content; Table USER1.CLOB_CONTENT: Columns: *ID NUMBER (38) NOT NULL CLOB_COLUMN CLOB NOT NULL 1 table found. (primary key columns are indicated with *) Command> INSERT INTO clob_content (id, clob_column) > VALUES (3, EMPTY_CLOB()); 1 row inserted. Command> UPDATE clob_content > SET clob_column = TO_CLOB('Demonstration of the TO_CLOB function.') > WHERE id = 3; 1 row updated.
The TO_DATE
function converts a CHAR
, VARCHAR2
, CLOB
, or NCLOB
argument to a value of DATE
data type.
If you are using TimesTen type mode, for information on the TO_DATE
function, see the Oracle TimesTen In-Memory Database Release 6.0.3 documentation.
TO_DATE
has the parameters:
Parameter | Description |
---|---|
Expression1 |
A CHAR , VARCHAR2 , CLOB , or NCLOB expression. |
Expression2 |
The format string. This expression is usually required. It is optional only when Expression1 is in the default date format YYYY-MM-DD HHMISS . |
Expression3 |
A CHAR or VARCHAR2 expression to specify the NLS parameter, which is currently ignored. |
You can use a datetime format model with the TO_DATE
function. For more information on datetime format models, see "Datetime format models".
Command> SELECT TO_DATE ('1999, JAN 14', 'YYYY, MON DD') FROM dual; < 1999-01-14 00:00:00 > 1 row found. Command> SELECT TO_CHAR(TO_DATE('1999-12:23','YYYY-MM:DD')) FROM dual; < 1999-12-23 00:00:00 > 1 row found. Command> SELECT TO_CHAR(TO_DATE('12-23-1997 10 AM:56:20', 'MM-DD-YYYY HH AM:MI:SS'), 'MONTH DD, YYYY HH:MI-SS AM') FROM DUAL; < DECEMBER 23, 1997 10:56-20 AM > 1 row found. Command> SELECT TO_CHAR(TO_DATE('12-23-1997 15:56:20', 'MM-DD-YYYY HH24:MI:SS'), 'MONTH DD, YYYY HH24:MI-SS') FROM DUAL; < DECEMBER 23, 1997 15:56-20 > 1 row found.
The TO_LOB
function converts supplied TT_VARCHAR
and VARCHAR2
data types to a CLOB
and VARBINARY
data types to a BLOB
.
TO_LOB
has the parameters:
Parameter | Description |
---|---|
ValidDataType |
A value that is of TT_VARCHAR , VARCHAR2 , or BINARY data types. |
You can use this function only on a TT_VARCHAR
, VARCHAR2
, or VARBINARY
column, and only with the CREATE TABLE AS SELECT
or INSERT...SELECT
statements on tables with a defined LOB column.
The following example shows how to use the TO_LOB
function within the INSERT...SELECT
statement on a table with a LOB column.
Command> CREATE TABLE clb(c CLOB); Command> CREATE TABLE vc (v VARCHAR2(2000)); Command> INSERT INTO vc(v) > VALUES ('Showing the functionality of the TO_LOB function'); 1 row inserted. Command> INSERT INTO clb SELECT TO_LOB(v) FROM vc; 1 row inserted. Command> SELECT * FROM clb; < Showing the functionality of the TO_LOB function > 1 row found.
Because of the restriction mentioned above, you cannot use the TO_LOB
function in all cases where you can use the TO_CLOB
or TO_BLOB
functions. The following example demonstrates the error you receive when you try to use the TO_LOB
function in this manner:
Command> SELECT TO_LOB(col1) > FROM bvar; 2610: Operand data type 'BINARY' invalid for operator 'TO_LOB' in expr ( TO_LOB( BVAR.COL1 )) The command failed.
The TO_NCLOB
function converts one of the following values to a NCLOB
:
Character value contained in one of the following data types: CHAR
, VARCHAR2
, NVARCHAR2
, TT_VARCHAR
, TT_NVARCHAR
, or NCLOB
Datetime value contained in a DATE
or TIMESTAMP
data type
Number value contained in a NUMBER
, BINARY_FLOAT
, or BINARY_DOUBLE
data type
TO_NCLOB
has the parameters:
Parameter | Description |
---|---|
ValidDataType |
A value of one of the valid data types mentioned above. |
The following converts the data in the VARCHAR2
job_title
column to be of data type NCLOB
.
Command> SELECT TO_NCLOB(job_title) FROM jobs; < Public Accountant > < Accounting Manager > < Administration Assistant > < President > < Administration Vice President > < Accountant > < Finance Manager > < Human Resources Representative > < Programmer > < Marketing Manager > < Marketing Representative > < Public Relations Representative > < Purchasing Clerk > < Purchasing Manager > < Sales Manager > < Sales Representative > < Shipping Clerk > < Stock Clerk > < Stock Manager > 19 rows found.
Converts an expression to a value of NUMBER
type.
TO_NUMBER
has the parameters:
Parameter | Description |
---|---|
Expression |
The expression to be converted, where the value can be of type CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , BINARY_FLOAT , BINARY_DOUBLE , CLOB , or NCLOB . |
Format |
If specified, the format is used to convert Expression to a value of NUMBER type. The format string identifies the number format model. The format and can be either a constant or a parameter. |
You can use a number format model with the TO_NUMBER
function. For more information on number format models, see "Number format models".
The TRIM
function trims leading or trailing characters (or both) from a character string.
There are four syntax options for TRIM
:
You can specify one of the TRIM
qualifiers (LEADING
or TRAILING
or BOTH
) with the Trim_character
:
TRIM ( LEADING|TRAILING|BOTH Trim_character FROM Expression )
You can specify one of the TRIM
qualifiers (LEADING
or TRAILING
or BOTH
) without the Trim_character
. In this case, Trim_character
defaults to a blank.
TRIM ( LEADING|TRAILING|BOTH FROM Expression )
You can specify the Trim_character
without one of the TRIM
qualifiers, which removes both leading and trailing instances of Trim_character
from Expression
.
TRIM (Trim_character FROM Expression )
You can specify the Expression
without a qualifier or a Trim_character
, which results in leading and trailing blank spaces removed from Expression
.
TRIM ( Expression )
TRIM
has the parameters:
Parameter | Description |
---|---|
LEADING | TRAILING | BOTH |
LEADING | TRAILING| BOTH are qualifiers to TRIM function. LEADING removes all leading instances of Trim_character from Expression . TRAILING removes all trailing instances of Trim_character from Expression . BOTH removes leading and trailing instances of Trim_character from Expression . |
[ Trim_character ] |
If specified, Trim_character represents the CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB or NCLOB operand or column used for trimming Expression . Must be only one character. If you do not specify Trim_character , it defaults to a single blank. If Trim_character is a character literal, enclose it in single quotes. |
Expression |
Expression is the CHAR , VARCHAR2 , NCHAR , NVARCHAR2 , CLOB or NCLOB operand or column to be trimmed. If Expression is a character literal, enclose it in single quotes. |
If Expression
is of type CHAR
or VARCHAR2
, the data type returned is VARCHAR2
. If Expression
is of type NCHAR
or NVARCHAR2
, the data type returned is NVARCHAR2
. If Expression
is of type CLOB
, the data type returned is CLOB
. If Expression
is of type NCLOB
, the data type returned is NCLOB
. The returned data type length is equal to the data type length of Expression
.
If Expression
is a data type defined with CHAR
length semantics, the returned length is expressed in CHAR
length semantics.
If either Trim_character
or Expression
is NULL
, the result is NULL
.
You can specify TT_CHAR
, TT_VARCHAR
, TT_NCHAR
, and TT_NVARCHAR
for Trim_character
and Expression
. If Expression
is of type TT_CHAR
or TT_VARCHAR
, the data type returned is TT_VARCHAR
. If Expression
is of type TT_NCHAR
or TT_NVARCHAR
, the data type returned is TT_NVARCHAR
.
If Trim_character
is of type NCHAR
or NVARCHAR2
and Expression
is of type CHAR
or VARCHAR2
, then Trim_character
is demoted to CHAR
or VARCHAR2
before TRIM
is invoked. The conversion of Trim_character
could be lost. If Trim_character
is not in the database character set, then the query may produce unexpected results.
For CHAR
, VARCHAR2
, NCHAR
, NVARCHAR2
, CLOB
and NCLOB
types:
If all the characters in Expression
are removed by the TRIM
function, the result is NULL
.
For TT_CHAR
, TT_VARCHAR
, TT_NCHAR
and TT_NVARCHAR
types:
If all the characters in Expression
are removed by the TRIM
function, the result is the empty string.
Use TRIM
function with qualifier to remove Trim_character
'0'
from Expression
'0000TRIM Example0000'
:
Command> SELECT TRIM (LEADING '0' FROM '0000TRIM Example0000') FROM dual; < TRIM Example0000 > 1 row found. Command> SELECT TRIM (TRAILING '0' FROM '0000TRIM Example0000') FROM dual; < 0000TRIM Example > 1 row found. Command> SELECT TRIM (BOTH '0' FROM '0000TRIM Example0000') FROM dual; < TRIM Example > 1 row found.
Use TRIM
function with qualifier to remove blank spaces. Do not specify a Trim_character
. Default value for Trim_character
is blank space:
Command> SELECT TRIM (LEADING FROM ' TRIM Example ') FROM dual; < TRIM Example > 1 row found. Command> SELECT TRIM (TRAILING FROM ' TRIM Example ') FROM dual; < TRIM Example > 1 row found. Command> SELECT TRIM (BOTH FROM ' TRIM Example ') FROM dual; < TRIM Example > 1 row found.
Use TRIM
function with Trim_character
'0'
. Do not specify a qualifier. Leading and trailing '0'
s are removed from Expression
'0000TRIM Example0000'
:
Command> SELECT TRIM ('0' FROM '0000TRIM Example0000') FROM dual; < TRIM Example > 1 row found.
Use TRIM
function without a qualifier or Trim_character
. Leading and trailing spaces are removed.
< TRIM Example > 1 row found. Command> SELECT TRIM (' TRIM Example ') FROM dual;
Returns date with the time portion of the day truncated to the unit specified by the format model fmt
. The value returned is of type DATE
. If you do not specify fmt
, then date
is truncated to the nearest day.
TRUNC (
date
)
has the parameters:
Parameter | Description |
---|---|
date |
The date that is truncated. Specify the DATE data type for date . The function returns data type DATE with the time portion of the day truncated to the unit specified by the format model. If you do not specify fmt , the date is truncated to the nearest day. An error is returned if you do not specify the DATE data type. |
[, fmt ] |
The format model truncating unit. Specify either a constant or a parameter for fmt . |
For the permitted format models to use in fmt
, see "Format model for ROUND and TRUNC date functions".
Returns a number truncated to a certain number of decimal places.
TRUNC
has the parameters:
Parameter | Description |
---|---|
Expression |
The Expression to truncate. Operands must be of type NUMBER . An error is returned if operands are not of type NUMBER . The value returned is of type NUMBER . |
[, m ] |
The number of decimal places to truncate to. If m is omitted, then the number is truncated to 0 places. The value of m can be negative to truncate (make zero) m digits left of the decimal point. |
The TT_HASH
function returns the hash value of an expression or list of expressions. This value is the value that is used by a hash index.
TT_HASH
has the parameter:
Parameter | Description |
---|---|
Expression [,...] |
One or more expressions to be used to determine the hash value of the expression or list of expressions. |
Each expression must have a known data type and must be non-nullable. The hash value of the expression depends on both the value of the expression and its type. For example, TT_HASH
of an TT_INTEGER
with value 25 may be different from TT_HASH
of a NUMBER
or BINARY_DOUBLE
with value 25. If you specify a list of expressions, the TT_HASH
result depends on the order of the expressions in the list.
Since constants and expressions that are not simple column references are subject to internal typing rules, over which applications have no control, the best way to ensure that TT_HASH
computes the desired value for expressions that are not simple column references is to CAST
the expression to the desired type.
The result type of TT_HASH
is TT_INTEGER
in 32-bit mode and TT_BIGINT
in 64-bit mode.
TT_HASH
can be used in a SQL statement anywhere an expression can be used. For example, TT_HASH
can be used in a SELECT
list, a WHERE
or HAVING
clause, an ORDER BY
clause, or a GROUP BY
clause.
The output of error messages, trace messages, and ttXactAdmin
display the hash value as a signed decimal so that the value matches TT_HASH
output.
When executed within a global query, gives the member ID in the cache grid of the owning member for each returned row.
TTGRIDMEMBERID()
, when executed within a global query, returns a TT_INTEGER
with the member ID of the member where each returned row is located in the cache grid. If not executed within a global query, the current member ID is returned. NULL
is returned if the member's node is not attached to a grid.
Autocommit should be set to OFF
.
See "Obtaining information about the location of data in the cache grid" in Oracle TimesTen Application-Tier Database Cache User's Guide for more information on this function.
The following example shows autocommit set to OFF
and sets the GlobalProcessing
optimizer hint to 1, which makes the statements following part of a global query. The SELECT
statement retrieves the employee number and member ID of the member where the employee data resides. The following output shows that the employee rows exist on members 2 and 4.
Command> AUTOCOMMIT OFF; Command> CALL ttOptSetFlag('GlobalProcessing', 1); Command> SELECT employee_id, TTGRIDMEMBERID() FROM employees; < 7900, 2 > < 7902, 4 > 2 rows found.
The following example uses TTGRIDMEMBERID()
in an ORDER BY
clause.
Command> AUTOCOMMIT OFF; Command> CALL ttOptSetFlag('GlobalProcessing', 1); Command> SELECT employee_id, TTGRIDMEMBERID() FROM employees ORDER BY TTGRIDMEMBERID(); < 7900, 2 > < 7902, 4 > 2 rows found.
The following example uses TTGRIDMEMBERID()
in a WHERE
clause:
Command> AUTOCOMMIT OFF; Command> CALL ttOptSetFlag('GlobalProcessing', 1); Command> SELECT employee_id, TTGRIDMEMBERID() FROM employees WHERE TTGRIDMEMBERID()=2; < 7900, 2 > 1 row found.
The following example executes TTGRIDMEMBERID()
as a local query to retrieve the local member ID, which is 1.
Command> SELECT TTGRIDMEMBERID() FROM dual; < 1 > 1 row found.
When executed within a global query, returns the name of the node in a cache grid on which the data is located.
TTGRIDNODENAME()
returns a TT_VARCHAR(64)
with the node name of the node on which each returned row is located, which shows the location of data in a cache grid. NULL
is returned if the node is not attached to a grid.
Autocommit should be set to OFF
.
See "Obtaining information about the location of data in the cache grid" in Oracle TimesTen Application-Tier Database Cache User's Guide for more information.
The following example shows autocommit set to OFF
and sets the GlobalProcessing
optimizer hint to 1, which makes the statements following part of a global query. The SELECT
statement retrieves the employee number and name of the node where the employee data resides. The following output shows that the employee rows exist on members 2 and 4.
Command> AUTOCOMMIT OFF; Command> CALL ttOptSetFlag('GlobalProcessing', 1); Command> SELECT employee_id, TTGRIDNODENAME() FROM employees; < 7900, MYGRID_member2 > < 7902, MYGRID_member4 > 2 rows found.
Within a global query, returns the user-assigned name of the node in a cache grid on which the data is located.
TTGRIDUSERASSIGNEDNAME()
returns a TT_VARCHAR(30)
with the node name assigned by the user to the node of the grid on which the data is located. NULL
is returned if the node is not attached to a grid.
Autocommit should be set to OFF
.
See "Obtaining information about the location of data in the cache grid" in Oracle TimesTen Application-Tier Database Cache User's Guide for more information.
The following example includes a cache grid whose members have user-assigned names alone1
, alone2
, and an active standby pair on nodes cacheact
and cachestand
. The standby database has the same data as the active database, but the query does not return data from the standby database.
The following example retrieves employee_id
and the user-assigned node name with TTGRIDUSERASSIGNEDNAME()
from the employees
table from the grid members. The returned rows show which grid node owns each row of the cache instance.
Command> AUTOCOMMIT OFF; Command> CALL ttOptSetFlag('GlobalProcessing', 1); Command> SELECT employee_id, TTGRIDUSERASSIGNEDNAME() FROM employees; Command> COMMIT; < 100, alone1> < 101, alone2> < 102, cacheact> < 103, alone1> < 104, cacheact> ...
Subsequent queries can access the appropriate node without changing the ownership of the data. For example, execute this query on grid node cacheact
, including TTGRIDUSERASSIGNEDNAME()
to verify that cacheact
is the node where the data is located:
Command> AUTOCOMMIT OFF; Command> CALL ttOptSetFlag('GlobalProcessing', 1); Command> SELECT employee_id, last_name, hire_date, TTGRIDUSERASSIGNEDNAME() FROM employees WHERE employee_id=104; < 104, Ernst, cacheact, 1991-05-21 00:00:00 >
The following example retrieves the employee number and user-assigned name for the node on which the employee data exists and orders the returned data by the user-assigned name:
Command> AUTOCOMMIT OFF; Command> CALL ttOptSetFlag('GlobalProcessing', 1); Command> SELECT employee_id, TTGRIDUSERASSIGNEDNAME() FROM employees ORDER BY TTGRIDUSERASSIGNEDNAME() ASC; < 7900, member2 > < 7902, member4 > 2 rows found.
The UNISTR
function takes as its argument a string that resolves to data of type NVARCHAR2
and returns the value in UTF-16 format. Unicode escapes are supported. You can specify the Unicode encoding value of the characters in the string.
UNISTR
has the parameter:
Parameter | Description |
---|---|
'String' |
The string passed to the UNISTR function. The string resolves to type NVARCHAR2 . TimesTen returns the value in UTF-16 format. You can specify Unicode escapes as part of the string. |