10 JUL

PostgreSQL GROUP BY Clause

Group by Clause is used to break the data into Groups.

Syntax:-
SELECT Column1, aggregate_function(Column2)
FROM TABLE
GROUP BY Column1;

employees is the table, that i’m going to use. here making department_id columns records into groups.

pic1

select department_id, using count aggregate function on department_id making department_id in groups.

counting total department_id

using max aggregate function on salary for counting maximum salary by department_id .

max salary on department

if we use group by clause on column then we cant use non aggregate columns on query.

non-aggregate column “empoyee_id”

After including employee_id in Group , No Error Found.

we can make group by multiple columns

Happy Queries, Thanks.

Post Author: adama