SQLWays converts DECODE function to CASE expression.

Oracle:

SELECT DECODE(warehouse_id, 1, 'Southlake', 2, 'San Francisco', 'Non domestic') FROM inventories;

HiRDB:

SELECT CASE warehouse_id WHEN 1 THEN 'Southlake' WHEN 2 THEN 'San Francisco' ELSE 'Non domestic' END FROM inventories;

References in Wiki