# Group rows together

Sometimes you need to group blocks of rows in a table and get some information on those groups of rows. For example, to get the average salary for each department

``````
CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
ENAME VARCHAR2(10),
JOB VARCHAR2(9),
SAL NUMBER(7, 2),
DEPTNO NUMBER(2));

INSERT INTO EMP VALUES (1, 'SMITH', 'CLERK',     800,    20);
INSERT INTO EMP VALUES (2, 'ALLEN', 'SALESMAN', 1600,    30);
INSERT INTO EMP VALUES (3, 'WARD',  'SALESMAN', 1250,    30);
INSERT INTO EMP VALUES (4, 'JONES', 'MANAGER',  2975,    20);
INSERT INTO EMP VALUES (5, 'MARTIN','SALESMAN', 1250,    30);
INSERT INTO EMP VALUES (6, 'BLAKE', 'MANAGER',  2850,    30);
INSERT INTO EMP VALUES (7, 'CLARK', 'MANAGER',  2850,    10);
INSERT INTO EMP VALUES (8, 'SCOTT', 'ANALYST',  3000,    20);
INSERT INTO EMP VALUES (9, 'KING',  'PRESIDENT',3000,    10);
INSERT INTO EMP VALUES (10,'TURNER','SALESMAN', 1500,    30);
INSERT INTO EMP VALUES (11,'ADAMS', 'CLERK',    1500,    20);

SQL> select avg(sal) from emp group by deptno;

AVG(SAL)
----------
1690
2068.75
2925

SQL>
``````

Using Multiple Columns in a Group:

``````
SQL> select avg(sal) from emp group by deptno, job;

AVG(SAL)
----------
1150
1400
2975
3000
2850
2850
3000

7 rows selected.

SQL>
``````
Home »
Oracle »
Select »

Group:
1. Group rows together
2. WHERE and GROUP BY Clauses
Related: