Using the CASE statement

A CASE statement is a widely used expression that takes in a list of conditions, evaluates the database column(s) referred to in the expression and, based on the evaluation of the field value, returns transformed values according to the rules defined.

It is a powerful and versatile tool that can be used to evaluate multiple conditions and return different results based on those conditions. It can be especially useful in scenarios where we need to handle different data types or values in a flexible and efficient way. It can be used in a few places in a SQL statement.

In this section, we’ll go through a few examples to showcase how to use it in SELECT, ORDER BY, UPDATE, and HAVING.

Using a simple CASE expression in a SELECT statement

The first way to use this expression is a simple version where the expression only looks at one field and only searches for the value from that field:

SELECT TOP(3) [Stock Holding Key], [Bin Location], [BinLocationDetailed...