Aggregate function

SQL Order of Operations

Using GROUP BY and HAVING

In this post, we discuss how to use the GROUP BY and HAVING clause in a T-SQL statement and how to use them with aggregate functions.

Coffee_Function

What is a Function?

What is a SQL Function and how to use a function in a T-SQL statement? We use the GetDate() and LEFT() functions as examples.

Aggregate_Functions

Using Aggregate Functions

How to use the COUNT, MAX, AVG, and SUM Aggregate Functions in a T-SQL statement.

NULL Values and Aggregate Functions

How to work with NULL values in Aggregate Functions in a T-SQL statement. How to fix issues with NULL values with the AVG() and COUNT() functions.