導讀:1建站知識sql不常用函數總結以及事務，增加，刪除觸發器，需要的朋友可以參考下網站建設多少錢如何seo優化推廣網站。

sql不常用函數總結以及事務，增加，刪除觸發器 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 ====================================================== 情況 case when xxx then xx when xxxx then xxxxx else end ======================================================= while xxx begin xxxxxx end 事務 ==============================================網站seo優化診斷工具===== 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 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 增加時觸發器 ========================================= create trigger tri_TblClass_insert_after on TblClass after inse網站建設公司rt as begin declare @id int declare @name varchar(50) declseo網站優化培訓are @desc varchar(50) select @id=tclassId,@name=tclassname,@desc=tclassdesc from inserted print @id print @name print @desc end ========================================= 刪除時觸發器 create trigger tri_TblClass_delete_after on TblClass instead of delete as begin insert into TblClassBak select * from deleted end ======================================== 作者 xhccom相關網站建設多少錢如何seo優化推廣網站。

關鍵詞標簽: 函數 觸發器