INSERT INTO qr_codes (user_id, total_qr_generate, total_qr_available) 
                     VALUES ('', '100', '100') Cannot add or update a child row: a foreign key constraint fails (`u891857582_paymentverse`.`qr_codes`, CONSTRAINT `qr_codes_ibfk_1` FOREIGN KEY (`user_id`) REFERENCES `users` (`id`) ON DELETE CASCADE)