A CASE expression can be used in place of any value-expression.
SELECT * FROM t WHERE x = CASE y WHEN 2 THEN 1001 WHEN 5 THEN 1002 END;
A CASE expression can be used in place of any value-expression.
SELECT * FROM t WHERE x = CASE y WHEN 2 THEN 1001 WHEN 5 THEN 1002 END;