触发器报错“Not allowed to return a result set from a trigger”的解决方案

创建触发器语句如下：

CREATE TRIGGER newproduct AFTER INSERT ON products
FOR EACH ROW SELECT 'Product added' ;

此时报错：
Not allowed to return a result set from a trigger

解决方法：加上 into @ee，因为从MySQL5以后不支持触发器返回结果集

CREATE TRIGGER newproduct AFTER INSERT ON products
FOR EACH ROW SELECT 'Product added' INTO @ee;