而 触发器主要是通过事件进行触发而被执行的. 例如当对某一表进行诸如UPDATE(修改)、INSERT(插入)、D...
如下： 在 mapper.xml 类型映射配置文件中 <insert id="insert" parameterType="com.hqdl.xiaoyi.bean...
IFEXISTS(SELECT1FROMsys.objectsWHEREname='tr_in_vt'ANDtype='TR')DROPTRIGGERtr_in_vt;GOCREATETRIGGERtr_in_vtONv_teacher INSTEADOFINSERTASDECLARE@pidint,@pnamevarchar(20),@psexvarchar(2),@tidint,@salarymoney;SELECTTOP1@pid=pid ,@pname=pname,@psex=psex,@tid=tid,@salary=salaryFROMinser...
在SQL Server 中,触发器(Triggers)是一种特殊的存储过程,它会在特定事件发生时自动执行。当涉及到对数据的插入(INSERT)、更新(UPDATE)或删除(DELETE)操作时,我们有两种主要的触发器类型:INSTEAD OF 触发器和 AFTER 触发器。本文将帮助您理解这两者的区别,并指导您如何实现它们。 触发器概述 触发器类型 流程概述 ...
{After|Insteadof} {insert|update|delete} as相应T-SQL语句 6. 修改触发器: 1 2 3 4 altertriggertrigger_name on{table_name|view_name} {After|Insteadof} {insert|update|delete} as相应T-SQL语句 7. 删除触发器: 1 droptriggertrigger_name ...
创建INSTEAD OF INSERT触发器 CREATETRIGGERtr_InsteadOfInsertONvw_Products INSTEADOFINSERTASBEGIN-- 执行自定义逻辑,比如插入数据到Products表INSERTINTOProducts(ID,Name,Price)SELECTID,Name,PriceFROMinserted;END; 1. 2. 3. 4. 5. 6. 7. 8.
INSTEAD OF INSERT trigger, however, any INSERT statement referencing the view must supply a value for the column. This value is required to build theinsertedtable passed to the trigger. A convention is required for a value that signals to the trigger that the default value should be used. ...
create trigger mytrg on 表名 instead of insert as declare myii begin select myii=count from inserted if(@myii>0)insert into 表名 select from inserted else begin --这里执行你说的"满足条件是触发"的事情 --范例中是count<=0执行的操作,这里我是不执行插入,所以什么都不需要写 end e...
本次练习将通过具体的例子介绍如何使用INSTEAD OF触发器,使读者掌握INSTEAD OF触发器的使用方法。 向student表中插入数据时,检查学号是否存在于student表中,如存在则进行插入操作,否则就不插入,具体语句如下所示: CREATE TRIGGER [checkid] ON dbo.student INSTEAD OF insert AS IF NOT EXISTS(SELECT * FROM dbo....
I have a table in SQL Server that utilises an INSTEAD OF trigger to update a column with a unix timestamp representing when the record was updated. When attempting to insert a record into this table from Entity Framework Core, a Microsof...