MySQL CASE Function
Example
Evaluate conditions and return a value when the first condition is met:
SELECT OrderID, Quantity,
CASE
WHEN Quantity > 30
THEN "The quantity is greater than 30"
WHEN Quantity =
30 THEN "The quantity is 30"
ELSE "The quantity is
something else"
END
FROM OrderDetails;
Try it Yourself »
Definition and Usage
The CASE function lets you evaluate conditions and return a value when the first condition is met (like an IF-THEN-ELSE statement).
Syntax
CASE expression
WHEN condition1 THEN result1
WHEN condition2 THEN result2
...
WHEN
conditionN THEN resultN
ELSE result
ENDParameter Values
| Parameter | Description |
|---|---|
| expression | Optional. The value to compare to the list of conditions |
| condition1, condition2, ...conditionN | Required. Evaluated in the order they are listed. Once a condition is true, the CASE function will return the result and not evaluate the conditions any further |
| result1, result2, ...resultN | Required. The value to return once a condition is true |
Note:
- If no condition is true, the CASE function will return the value in the ELSE clause
- If the ELSE clause is omitted and no condition is true, the CASE function will return NULL
Technical Details
| Works in: | MySQL 5.7, MySQL 5.6, MySQL 5.5, MySQL 5.1, MySQL 5.0, MySQL 4.1, MySQL 4.0, MySQL 3.23 |
|---|
More Examples
Example
Evaluate conditions and return a value when the first condition is met:
SELECT CustomerName, City, Country
FROM Customers
ORDER BY
(CASE
WHEN City IS NULL THEN Country
ELSE City
END);
Try it Yourself »
