Isnull in mysql

Problem

There are many date, string, numeric and aggregate functions built in to SQL Server that make our lives easier when writing queries. These SQL functions are broken up into different categories and in this tutorial we will look at the system function ISNULL().

Solution

Note: Some examples below are based on the AdventureWorks2017 database schema, those that are not have complete DDL noted so you can try the examples yourself (these must be run in a separate database, not in AdventureWorks2017).

Incorrect parameter count in the call to native function 'isnull'

All examples were tested using SQL Server 2019 (15.0.2070.41).

The built in system functions in Microsoft SQL Server are used to perform system operations and return information about objects or settings in SQL Server.

The ISNULL() function is used to check if a value is null and if it is will return the replacement value specified when calling the function.

Understanding NULL Values

Before we get into the details of the function it is important to make sure we understand what a NULL value is in SQL Server.

A NULL value is a special marker i

sql server isnull not working

sql server isnull example