How can you use the CASE clause for conditional selection?
Using the CASE Clause in MySQL
In MySQL, the CASE clause allows you to perform conditional logic directly within a query. It can be used in SELECT, ORDER BY, GROUP BY, or even WHERE clauses to return values based on conditions.
Key Features of the CASE Clause
Evaluates conditions sequentially and returns the value for the first true condition.
Supports a default result using the
ELSEkeyword if none of the conditions match.Can be used to categorize data or perform conditional calculations in the result set.
Syntax:
CASE WHEN condition1 THEN result1 WHEN condition2 THEN result2 ELSE result_default END
The CASE clause is extremely useful for transforming data on the fly, creating computed columns, or applying conditional logic without changing the underlying data.
Example of CASE Clause Usage