SQL Server触发器和事务用法示例

2023年 4月 20日 46.3k 0

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,deleteasbegin set XACT_ABORT ON declare @INSERTCOUNT int; declare @DE

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。

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