讲解Microsoft SQL Server的行式触发器

7/10/2008来源:SQL技巧人气:5074

曾经以为SQL SERVER的触发器只能触发单行,也就是说如果一个delete触发器,如果同时删除多行时,只会对第一条记录触发,后来发现了不是人家SQL SERVER不支持,而是偶脑子笨没发现。


其实inserted和deleted两张内部表存放了所有要插入或要删除的记录,可以用cursor逐次访问里面的每条记录,下面是一个示例,该触发器将要删除的记录转移到另一张表中:


第一步,创建这两张表


create table table1([id] int PRimary key, [value] varchar(100))create table table2([id] int primary key, [value] varchar(100))

第二步,插入测试数据


declare @i intset @i = 1while @i <= 100begin insert into table1([id], [value]) values(@i, cast(@i as varchar)) set @i = @i + 1end

创建table1的delete触发器


create trigger tr_d_table1 on table1 for deleteasbegin declare @id int, @value varchar(100) declare cur_del cursor local forward_only for select [id], [value] from deleted open cur_del fetch next from cur_del into @id, @value while @@fetch_status = 0 begin insert into table2([id], [value]) values(@id, @value) fetch next from cur_del into @id, @value end close cur_del deallocate cur_del end

现在对table1执行delete语句,发现所有被删除的记录都记录在在table2中了

delete from table1