MySQL Case Operator

The MySQL allows you to write complex conditional construct with the help of CASE operator. In other words, CASE operator for stored programs implements a complex conditional construct.

MySQL CASE OPERATOR Syntax

To write complex conditional construct, use the following syntax:

SELECT Col1, Col2 .....,
CASE WHEN [condition] THEN result 
[ELSE result] 
END
FROM tablename;

Parameters:

tablename: The table name from which you want to fetch the records.

condition: To check conditions is true or not.

result: If condition fails, return default result.

MySQL CASE OPERATOR example

SELECT firstName, lastName, address,
CASE WHEN firstName = 'Dilip' THEN 'Found' 
ELSE 'Not Found' END AS Status
FROM tblCustomerLoan;

Note:

In the above example, we are checking each string in "firstName" column, if value = "Dilip" then return "Found" value else return "Not Found" value as result.

You can use MySQL Command Line Client to write complex conditional construct in a stored program. It will look like this: