SQL Server触发器和事务用法示例
编程学习 2021-07-05 13:43www.dzhlxh.cn编程入门
这篇文章主要介绍了SQL Server触发器和事务用法,结合实例形式分析了SQL Server触发器、事务、存储过程、游标、视图等的相关定义与使用方法,需要的朋友可以参考下
本文实例讲述了SQL Server触发器和事务用法。分享给大家供大家参考,具体如下:
新增和删除触发器
alter trigger tri_TC on t_c for INSERT,delete as begin set XACT_ABORT ON declare @INSERTCOUNT int; declare @DELETECOUNT int; declare @UPDATECOUNT int; set @INSERTCOUNT = (select COUNT(*) from inserted); set @DELETECOUNT = (select COUNT(*) from deleted); set @UPDATECOUNT = () if(@INSERTCOUNT > 0) begin insert into t_c2 select * from inserted; end else if(@DELETECOUNT > 0) begin delete t_c2 where exists(select temp.cid from deleted temp where temp.cid=t_c2.cid); end end
更新触发器和事务
事务主要用在数据的保护,在多表更新时,事务保存所有事务下的更新语句就不会提交,数据也就不能更新成功
alter trigger tri_TC_Update on t_c for update as begin declare @delcount int; set @delcount = (select count(*) from deleted); if(@delcount > 0) begin begin transaction triUpdate --定义事务 declare @cname varchar(100); select @cname = cname from inserted; --保存更新后的内容 update t_c2 set cname = @cname where cid = (select cid from deleted); --更新 if (@@error <> 0) begin rollback transaction triUpdate; --事务回滚 end else begin commit transaction triUpdate; --事务提交 end end end
存储过程
if(exists(select name from sysobjects s where s.name='pro_fun' and s.type='p')) drop procedure pro_fun go create procedure pro_fun as select * from table go exec pro_fun
游标
declare @qybh varchar(10) declare cur cursor for select distinct qybh from PJ_EnterpriseInput open cur fetch next from cur into @qybh while @@fetch_status = 0 begin print(@qybh) fetch next from cur into @qybh end close cur deallocate cur
视图
alter view CreateView as select qybh from CreateView go
定义方法
alter function funName(@str1 varchar(10),@str2 varchar(10)) returns varchar(10) as begin declare @returnStr varchar(10) set @returnStr = 'false' if(@str1 > @str2) set @returnStr = 'true' return @returnStr end select dbo.funName(... , ...)
定义表变量
declare @qybhTable table (id varchar(32),qybh varchar(30)) insert into @qybhTable select id,qybh from PJ_EnterpriseInput select * from @qybhTable
case when then 条件统计时的使用
select sum(case when z.watchName='注册监理工程师' then 1 else 0 end), sum(case when z.watchName='xinza' then 1 else 0 end), sum(case when z.watchName='监理员' then 1 else 0 end) from zu_corjl z right join zu_corjltemp t on t.corID=z.corID
希望本文所述对大家SQL Server数据库程序设计有所帮助。