OraBFILE Object

Description

The OraBFile interface in OO4O provides methods for performing operations on the BFILE LOB data type in the database.

Remarks

The BFILE types are large binary data objects stored in operating system files (external) outside of the database tablespaces.

Properties

• DirectoryName Property

• FileName Property

• Exists Property

• IsNull (OraLOB/BFILE) Property

• IsOpen (OraBFILE) Property

• Offset (OraLOB/BFILE) Property

• PollingAmount Property

• Size (OraLOB and OraBFILE) Property

• Status (OraLOB/BFILE) Property

Methods

• Clone (OraLOB/BFILE) Method

• Close (OraBFILE) Method

• CloseAll (OraBFILE) Method

• Compare (OraLOB) Method

• CopyToFile (OraLOB/BFILE) Method

• MatchPos (OraLOB/BFILE) Method

• Open (OraBFILE) Method

• Read (OraLOB/BFILE) Method

Examples

See "Schema Objects Used in LOB Data Type Examples" for schema objects that are used in the OraLOB/BFILE examples.

NOTE: To add the required tables for the following examples, run the lob.sql file in the \OO4O\VB\SAMPLES\LOB directory.

Example: Accessing the BFILE Value

BFILE data can be read using the Read method. The OraBFILE object allows piecewise read operations. Before reading the BFILE content, the BFILE file should be opened using the Open method.

Dim PartColl as OraBFile 
Dim buffer As Variant 
 
'Create a Dynaset containing a BLOB and a CLOB column 
set part = OraDatabase.CreateDynaset ("select * from part",0) 
Set PartColl = part.Fields("part_collateral").Value 
 
'open the bfile for read operation 
PartColl.Open 
 
'read the entire bfile 
amount_read = PartColl.Read(buffer)
 
'close the bfile 
PartColl.Close 

Example: Reading and Inserting BFILEs Using Dynasets

To modify the directory and file names of the BFILE value of an OraBFILE object, first obtain a lock and then use the DirectoryName and FileName properties.

To insert a new row containing a BFILE column, initialize the BFILE column with new directory and file name values using the DirectoryName and FileName properties.

Dim PartColl as OraBFile 
Dim buffer As Variant 
 
'Create a Dynaset containing a BLOB and a CLOB column 
set part = OraDatabase.CreateDynaset ("select * from part",0) 
Set PartColl = part.Fields("part_collateral").Value 
 
'insert a new BFILE in the part_collateral column 
part.AddNew 
 
'Directory objects will be upper-case by default 
    PartColl.DirectoryName = "NEWDIRECTORYNAME"  
    PartColl.FileName = "NewPartCollatoral" 
part.Update 
 
'move to the newly added row 
part.MoveLast 
 
'open the Bfile for read operation 
PartColl.Open 
 
'read the entire bfile 
amount_read = PartColl.Read(buffer)
 
'close the Bfile 
PartColl.Close