PL/pgSQL CASE Statement

DO $$
DECLARE
    Snapdragon  INTEGER := 855;
    MediatekP   INTEGER := 70;
    Exynos      INTEGER := 9820;
BEGIN
    CASE

    WHEN Snapdragon > 845 THEN
    RAISE NOTICE 'MI 9 uses a Snapdragon 855 processor';

    WHEN MediatekP < 60 THEN
    RAISE NOTICE 'Realme U1 uses a Mediatek P70 processor';

    WHEN Exynos < 9810 THEN
    RAISE NOTICE 'Samsung Galaxy S10+ uses a Exynos 9820 processor';

    ELSE
    RAISE NOTICE 'Not Found';

    END CASE;
END $$;