![]() ![]() If the evaluated value is the same the as the set value, the result defined in THEN is returned. In a simple CASE expression, the name of the column or expression to be evaluated is absolutely necessary. Here's what the syntax looks like: CASE column_or_expression WHEN value THEN when_result If it meets a WHEN condition, the THEN result is returned. The simple CASE compares a value to one or more WHEN conditions. Each one has a slightly different syntax, and each works a little differently. There are two types of CASE expressions: simple and searched. If ELSE is not defined and WHEN is not met, a NULL will be returned. An optional ELSE statement determines the result returned if the WHEN condition is not met. After the WHEN clause, we see the condition or value to compare the THEN determines the result if the condition is met. The WHEN and THEN keywords define the logical conditions. The names of specific columns or expressions are entered after the CASE keyword. The expression starts with the CASE keyword and ends with the END keyword. The basic syntax of the CASE expression is presented below: CASE We'll look at both, but first we will start with the basic syntax of this expression. You should know that there are two kinds of CASE expressions: simple and searched. It contains almost 100 exercises and is focused on using CASE in different practical SQL problems. To practice using CASE statement after reading this article, I recommend our interactive course Creating Basic SQL Reports. ![]() We'll focus on the SELECT statement and use IN and LIKE operators. This expression can be used in SELECT, UPDATE, and DELETE statements or in WHERE, IN, LIKE, ORDER BY, and HAVING clauses. The result it returns is based on whether the data meets certain criteria. The CASE expression is a conditional expression: it evaluates data and returns a result. In this article, we'll introduce you to the syntax, formats, and uses of the CASE expression. The simple way to achieve this goal is to add a CASE expression to your SELECT statement. As you write an SQL query, you may need to get values from multiple columns and change values from one form to another. ![]()
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