This article describes how to use the
T-SQL Aggregate functions in SQL Server database.
Aggregate functions perform a calculation on a set of values and return a single value.
SQL Server aggregate functions are: AVG, SUM, MAX, MIN, COUNT.
SQL Server Aggregate functions are used to calculate and return the sum, average, minimum, or maximum value of a column in a table. You can also use it to calculate the number of rows in a table or the distinct values in a column.
AVG function returns the average value.
select avg(price) from courses;
select name, price
group by name, price
having avg(price) > 70;
SUM function returns the sum of all values.
select sum(price) from courses;
where price > 50;
MAX function returns the max value.
select max(price) from courses;
where price < 70;
MIN function returns the min value.
select min(price) from courses;
where price > 70;
COUNT function returns the number of rows returned by a query.
select count(*) from courses;
select count(*), price
group by price
having count(*) = 2;