原始sql: create trigger testEmpno after insert on emp for each row select NEW.empno；
错误：[Err] 1415 - Not allowed to return a result set from a trigger
原因：从MySQL5以后不支持触发器返回结果集
解决方法：
sql语句:create trigger testEmpno after insert on emp for each row select NEW.empno INTO @ee ;