How to use Aggregate Functions in SQL Server

SQL Aggregate Functions

Following are the most used Sql aggregate functions

MAX()

MIN()

AVG()

SUM()

COUNT()            

Here  is the brief description about the each function.

MAX() Function

The MAX() function returns the largest value of the selected column.

SQL MAX() Syntax : 

select max(salary) from Sal

MIN() Function

The MIN() function returns the smallest value of the selected column.

Syntax: 

select min(salary) from Sal

AVG() Function

The AVG() function returns the average value of a numeric column.

SQL AVG() Syntax: 

select avg(salary) from Sal

SUM() Function

The SUM() function returns the total sum of a numeric column.

Syntax: 

select sum(salary) from Sal

Top keyword

The SELECT TOP clause is used to specify the number of records to return.

Syntax: 

select top (1,2,..,n-1,n)(salary) from Sal

COUNT() Function

The COUNT() function returns the number of rows that matches a specified criteria

Syntax: 

select count(salary) from Sal