STATS_MODE
takes as its argument a set of values and returns the value that occurs with the greatest frequency. If more than one mode exists, then Oracle Database chooses one and returns only that one value.
To obtain multiple modes (if multiple modes exist), you must use a combination of other functions, as shown in the hypothetical query:
SELECT x FROM (SELECT x, COUNT(x) AS cnt1 FROM t GROUP BY x) WHERE cnt1 = (SELECT MAX(cnt2) FROM (SELECT COUNT(x) AS cnt2 FROM t GROUP BY x));
The following example returns the mode of salary per department in the hr.employees
table:
SELECT department_id, STATS_MODE(salary) FROM employees GROUP BY department_id ORDER BY department_id, stats_mode(salary); DEPARTMENT_ID STATS_MODE(SALARY) ------------- ------------------ 10 4400 20 6000 30 2500 40 6500 50 2500 60 4800 70 10000 80 9500 90 17000 100 6900 110 8300 7000
If you need to retrieve all of the modes (in cases with multiple modes), you can do so using a combination of other functions, as shown in the next example:
SELECT commission_pct FROM (SELECT commission_pct, COUNT(commission_pct) AS cnt1 FROM employees GROUP BY commission_pct) WHERE cnt1 = (SELECT MAX (cnt2) FROM (SELECT COUNT(commission_pct) AS cnt2 FROM employees GROUP BY commission_pct)) ORDER BY commission_pct; COMMISSION_PCT -------------- .2 .3