USE dating_app;

-- Replace the named CHECK in one ALTER when the server enforces it.
-- MySQL 5.7 accepts but does not enforce CHECK constraints.
SET @direction_check_exists = (
    SELECT COUNT(*)
    FROM information_schema.TABLE_CONSTRAINTS
    WHERE CONSTRAINT_SCHEMA = DATABASE()
      AND TABLE_NAME = 'swipes'
      AND CONSTRAINT_NAME = 'ck_swipe_direction'
      AND CONSTRAINT_TYPE = 'CHECK'
);
SET @statement = IF(
    @direction_check_exists > 0,
    'ALTER TABLE swipes DROP CHECK ck_swipe_direction, ADD CONSTRAINT ck_swipe_direction CHECK (direction IN (''like'', ''pass'', ''super_like''))',
    'ALTER TABLE swipes ADD CONSTRAINT ck_swipe_direction CHECK (direction IN (''like'', ''pass'', ''super_like''))'
);
PREPARE migration_statement FROM @statement;
EXECUTE migration_statement;
DEALLOCATE PREPARE migration_statement;