SQL GROUP BY

The GROUP BY statement is used in conjunction with the aggregate functions to group the result-set by one or more columns.

Syntax 

SELECT column_name, aggregate_function(column_name)
FROM table_name
WHERE column_name operator value
GROUP BY column_name 


The "Custmast" table 

custcode	custname	city	qty	rate
1	Siva	Srivilliputtur	50	70
2	Bala	Sivakasi	30	56
3	Kanna	Madurai	100	200
4	Vijay	Chennai	30	30
5	Kodee	Sandnes	60	80
5	Kodee	Srivilliputtur	60	30

Example :


Now we want to find the total sum (Qty) of each customer.

Select Custname,Sum(Qty)  as Tot From Custmast 

Group by CustName

custname	Tot
Siva	50
Bala	30
Kanna	100
Vijay	30
Kodee	120

Group By More than One Column

SELECT Custname,City,SUM(Qty) as Tot FROM Orders
GROUP BY Custname,City