Oracle Database Interview Question:

Can Multiple Columns Be Used in GROUP BY in Oracle?

Submitted by: Administrator

You can use multiple columns in the GROUP BY clause as shown in the following example. It returns how many employees are having the same salary in each department:

SQL> SELECT department_id, salary, count(*)
2 FROM employees GROUP BY department_id,
3 salary HAVING count(*) > 1;
<pre>DEPARTMENT_ID SALARY COUNT(*)
------------- ---------- ----------
90 17000 2
50 3200 4
50 2200 2
50 3600 2
80 10500 2
80 9000 2
50 2700 2
......</pre>
Submitted by: Administrator