91. GROUP FUNCTIONS

Ø  Sum

Ø  Avg

Ø  Max

Ø  Min

Ø  Count

Group functions will be applied on all the rows but produces single output.

a) SUM

     This will give the sum of the values of the specified column.

     Syntax: sum (column)

     Ex:

          SQL> select sum(sal) from emp;

  SUM(SAL)

   ----------

     38600

b) AVG

     This will give the average of the values of the specified column.

     Syntax: avg (column)

     Ex:

          SQL> select avg(sal) from emp;

   AVG(SAL)

   ---------------

   2757.14286

c) MAX

     This will give the maximum of the values of the specified column.

     Syntax: max (column)

     Ex:

          SQL> select max(sal) from emp;

    MAX(SAL)

   ----------

     5000

        d) MIN

     This will give the minimum of the values of the specified column.

     Syntax: min (column)

     Ex:

          SQL> select min(sal) from emp;

   MIN(SAL)

   ----------

     500

e) COUNT

     This will give the count of the values of the specified column.

     Syntax: count (column)

     Ex:

          SQL> select count(sal),count(*) from emp;

COUNT(SAL)   COUNT(*)

--------------    ------------

        14                     14