主頁 > 知識庫 > sql不常用函數(shù)總結以及事務,增加,刪除觸發(fā)器

sql不常用函數(shù)總結以及事務,增加,刪除觸發(fā)器

熱門標簽:網(wǎng)站排名優(yōu)化 AI電銷 地方門戶網(wǎng)站 百度競價排名 呼叫中心市場需求 Linux服務器 鐵路電話系統(tǒng) 服務外包
sql不常用函數(shù)總結以及事務,增加,刪除觸發(fā)器

distinct 刪除重復行

declare @x 申明一個變量

convert(varchar(20),tscore.tenglish) 類型轉換

cast(xx as varchar(10)) 類型轉換
www.jb51.net
======================================================

情況
case
when xxx then xx
when xxxx then xxxxx
else
end

=======================================================

while xxx
begin
xxxxxx
end
www.jb51.net
事務
===================================================
begin tran
declare @sum int = 0
update bank set balance=balance-1000 where cid='0001'
set @sum=@sum+@@error
update bank set balance=balance + 1000 where cid='0002'
set @sum=@sum+@@error

if @sum>0
begin
rollback
print '回滾!'
end
else
begin
--提交事務
commit tran
print '提交了!'
end
===================================================
begin tran www.jb51.net
begin try
declare @sum int = 0
update bank set balance=balance-900 where cid='0001'
set @sum=@sum+@@error
update bank set balance=balance + 900 where cid='0002'
set @sum=@sum+@@error
commit
end try
begin catch
rollback
end catch
=====================================================

declare @halfCount int= ceiling(@count/2.0) 向上

增加時觸發(fā)器
=========================================
create trigger tri_TblClass_insert_after
on TblClass after insert
as
begin
declare @id int
declare @name varchar(50)
declare @desc varchar(50)
select @id=tclassId,@name=tclassname,@desc=tclassdesc from inserted

print @id
print @name
print @desc
end www.jb51.net
=========================================

刪除時觸發(fā)器
create trigger tri_TblClass_delete_after
on TblClass instead of delete
as
begin

insert into TblClassBak
select * from deleted
end
========================================


作者 xhccom

標簽:仙桃 崇左 黃山 衡水 銅川 湘潭 湖南 蘭州

巨人網(wǎng)絡通訊聲明:本文標題《sql不常用函數(shù)總結以及事務,增加,刪除觸發(fā)器》,本文關鍵詞  ;如發(fā)現(xiàn)本文內容存在版權問題,煩請?zhí)峁┫嚓P信息告之我們,我們將及時溝通與處理。本站內容系統(tǒng)采集于網(wǎng)絡,涉及言論、版權與本站無關。
  • 相關文章
  • 收縮
    • 微信客服
    • 微信二維碼
    • 電話咨詢

    • 400-1100-266