我得到这个错误：错误代码：1064。sql语法有错误；请查看与mysql服务器版本对应的手册，以获取第7行“”附近要使用的正确语法
在以下查询中：

DELIMITER //
create trigger UpdateTrigger 
    after update
        on reserva for each row
begin
IF NEW.reserva_valida = 0 THEN
    DELETE FROM companhia_aerea.venda 
    where companhia_aerea.venda = NEW.reserva_id;
END IF;
end;
DELIMITER ;

我就是这样创建这两个表的：
预订：

CREATE TABLE IF NOT EXISTS `companhia_aerea`.`reserva` (
  `reserva_id` INT NOT NULL AUTO_INCREMENT,
  `reserva_data_validade` DATE NOT NULL,
  `reserva_valida` TINYINT NOT NULL,
  `reserva_voo_id` INT NOT NULL,
  `reserva_venda_id` INT NOT NULL,
  PRIMARY KEY (`reserva_id`),
  INDEX `fk_reserva_voo1_idx` (`reserva_voo_id` ASC) VISIBLE,
  INDEX `fk_reserva_venda1_idx` (`reserva_venda_id` ASC) VISIBLE,
  CONSTRAINT `fk_reserva_voo1`
    FOREIGN KEY (`reserva_voo_id`)
    REFERENCES `companhia_aerea`.`voo` (`voo_id`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION,
  CONSTRAINT `fk_reserva_venda1`
    FOREIGN KEY (`reserva_venda_id`)
    REFERENCES `companhia_aerea`.`venda` (`venda_id`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION)
ENGINE = InnoDB;

文达：

DROP TABLE IF EXISTS companhia_aerea.venda;
CREATE TABLE IF NOT EXISTS `companhia_aerea`.`venda` (
  `venda_id` INT NOT NULL AUTO_INCREMENT,
  `reserva_id` INT NOT NULL,
  `venda_parcelas` INT NOT NULL,
  PRIMARY KEY (`venda_id`))
ENGINE = InnoDB;