SQL GROUP BY Clause

The SQL GROUP BY Clause is used along with the group functions to retrieve data grouped according to one or more columns.


For Example: If you want to know the total amount of salary spent on each department, the query would be:


SELECT dept, SUM (salary)

FROM employee

GROUP BY dept;


The output would be like:


dept salary

---------------- --------------

Electrical 25000

Electronics 55000

Aeronautics 35000

InfoTech 30000

NOTE: The group by clause should contain all the columns in the select list expect those used along with the group functions.


SELECT location, dept, SUM (salary)

FROM employee

GROUP BY location, dept;


The output would be like:


location dept salary

------------- --------------- -----------

Bangalore Electrical 25000

Bangalore Electronics 55000

Mysore Aeronautics 35000

Mangalore InfoTech 30000