W3Schools SQL | #32 SQL CASE 문법

SQL CASE Expression

The SQL CASE Expression

C언어의 case와 동일한 기능

CASE Syntax

CASE
    WHEN condition1 THEN result1
    WHEN condition2 THEN result2
    WHEN conditionN THEN resultN
    ELSE result
END;

SQL CASE Examples

SELECT OrderID, Quantity, 
CASE
    WHEN Quantity > 30 THEN 'The qunatity is greater than 30'
    WHEN Quantity = 30 THEN 'The quantity is 30'
    ELSE 'The quantity is under 30'
END AS QuantityText
FROM OrderDetails;

SELECT CustomerName, City, Country
FROM Customers
ORDER BY (
    CASE 
        WHEN City IS NULL THEN Country
        ELSE City
    END
);