--有輸入參數的存儲過程--create proc GetComment(@commentid int)asselect * from Comment where CommentID=@commentid --有輸入與輸出參數的存儲過程--create proc GetCommentCount@newsid int,@count int outputasselect @count=count(*) from Comment where NewsID=@newsid --返回單個值的函數--create function MyFunction(@newsid int)returns intasbegindeclare @count intselect @count=count(*) from Comment where NewsID=@newsidreturn @countend --調用方法--declare @count intexec @count=MyFunction 2print @count --返回值為表的函數--Create function GetFunctionTable(@newsid int)returns tableasreturn(select * from Comment where NewsID=@newsid) --返回值為表的函數的調用--select * from GetFunctionTable(2)
SQLServer 存儲過程中不拼接SQL字符串實現多條件查詢
--以前拼接的寫法 set @sql=' select * from table where 1=1 ' if (@addDate is not null) set @sql = @sql+' and addDate = '+ @addDate + ' ' if (@name <>'' and is not null) set @sql = @sql+ ' and name = ' + @name + ' ' exec(@sql)
下面是 不采用拼接SQL字符串實現多條件查詢的解決方案
--第一種寫法是 感覺代碼有些冗余 if (@addDate is not null) and (@name <> '') select * from table where addDate = @addDate and name = @name else if (@addDate is not null) and (@name ='') select * from table where addDate = @addDate else if(@addDate is null) and (@name <> '') select * from table where and name = @name else if(@addDate is null) and (@name = '') select * from table --第二種寫法是 select * from table where (addDate = @addDate or @addDate is null) and (name = @name or @name = '') --第三種寫法是 SELECT * FROM table where addDate = CASE @addDate IS NULL THEN addDate ELSE @addDate END, name = CASE @name WHEN '' THEN name ELSE @name END
SQLSERVER存儲過程基本語法
一、定義變量
--簡單賦值declare @a intset @a=5print @a --使用select語句賦值declare @user1 nvarchar(50)select @user1= '張三'print @user1declare @user2 nvarchar(50)select @user2 = Name from ST_User where ID=1print @user2 --使用update語句賦值declare @user3 nvarchar(50)update ST_User set @user3 = Name where ID=1print @user3
二、表、臨時表、表變量
--創建臨時表1create table #DU_User1( [ID] [ int ] NOT NULL , [Oid] [ int ] NOT NULL , [Login] [nvarchar](50) NOT NULL , [Rtx] [nvarchar](4) NOT NULL , [ Name ] [nvarchar](5) NOT NULL , [ Password ] [nvarchar]( max ) NULL , [State] [nvarchar](8) NOT NULL);--向臨時表1插入一條記錄insert into #DU_User1 (ID,Oid,[Login],Rtx, Name ,[ Password ],State) values (100,2, 'LS' , '0000' , '臨時' , '321' , '特殊' ); --從ST_User查詢數據，填充至新生成的臨時表select * into #DU_User2 from ST_User where ID<8 --查詢并聯合兩臨時表select * from #DU_User2 where ID<3 union select * from #DU_User1 --刪除兩臨時表drop table #DU_User1drop table #DU_User2 --創建臨時表CREATE TABLE #t( [ID] [ int ] NOT NULL , [Oid] [ int ] NOT NULL , [Login] [nvarchar](50) NOT NULL , [Rtx] [nvarchar](4) NOT NULL , [ Name ] [nvarchar](5) NOT NULL , [ Password ] [nvarchar]( max ) NULL , [State] [nvarchar](8) NOT NULL ,) --將查詢結果集（多條數據）插入臨時表insert into #t select * from ST_User--不能這樣插入--select * into #t from dbo.ST_User --添加一列，為int型自增長子段alter table #t add [myid] int NOT NULL IDENTITY(1,1)--添加一列，默認填充全球唯一標識alter table #t add [myid1] uniqueidentifier NOT NULL default (newid()) select * from #tdrop table #t--給查詢結果集增加自增長列 --無主鍵時：select IDENTITY( int ,1,1) as ID, Name ,[Login],[ Password ] into #t from ST_Userselect * from #t --有主鍵時：select ( select SUM (1) from ST_User where ID<= a.ID) as myID,* from ST_User a order by myID--定義表變量declare @t table( id int not null , msg nvarchar(50) null)insert into @t values (1, '1' )insert into @t values (2, '2' )select * from @t
三、循環
--while循環計算1到100的和declare @a intdeclare @ sum intset @a=1set @ sum =0while @a<=100begin set @ sum +=@a set @a+=1endprint @ sum
四、條件語句
--if,else條件分支if(1+1=2)begin print '對'endelsebegin print '錯'end --when then條件分支declare @today intdeclare @week nvarchar(3)set @today=3set @week= case when @today=1 then '星期一' when @today=2 then '星期二' when @today=3 then '星期三' when @today=4 then '星期四' when @today=5 then '星期五' when @today=6 then '星期六' when @today=7 then '星期日' else '值錯誤'endprint @week
五、游標
declare @ID intdeclare @Oid intdeclare @Login varchar (50) --定義一個游標declare user_cur cursor for select ID,Oid,[Login] from ST_User--打開游標open user_curwhile @@fetch_status=0begin--讀取游標 fetch next from user_cur into @ID,@Oid,@Login print @ID --print @Loginendclose user_cur--摧毀游標deallocate user_cur
五、游標
declare @ID intdeclare @Oid intdeclare @Login varchar (50) --定義一個游標declare user_cur cursor for select ID,Oid,[Login] from ST_User--打開游標open user_curwhile @@fetch_status=0begin--讀取游標 fetch next from user_cur into @ID,@Oid,@Login print @ID --print @Loginendclose user_cur--摧毀游標deallocate user_cur
六、觸發器
觸發器中的臨時表：
Inserted
存放進行insert和update 操作后的數據
Deleted
存放進行delete 和update操作前的數據
--創建觸發器Create trigger User_OnUpdate On ST_User for Update As declare @msg nvarchar(50) --@msg記錄修改情況 select @msg = N '姓名從“' + Deleted. Name + N '”修改為“' + Inserted. Name + '”' from Inserted,Deleted --插入日志表 insert into [LOG](MSG) values (@msg) --刪除觸發器drop trigger User_OnUpdate
七、存儲過程
--創建帶output參數的存儲過程CREATE PROCEDURE PR_Sum @a int , @b int , @ sum int outputASBEGIN set @ sum =@a+@bEND --創建Return返回值存儲過程CREATE PROCEDURE PR_Sum2 @a int , @b intASBEGIN Return @a+@bEND --執行存儲過程獲取output型返回值declare @mysum intexecute PR_Sum 1,2,@mysum outputprint @mysum --執行存儲過程獲取Return型返回值declare @mysum2 intexecute @mysum2= PR_Sum2 1,2print @mysum2
八、自定義函數
函數的分類：
1）標量值函數
2）表值函數
a:內聯表值函數
b:多語句表值函數
3）系統函數
--新建標量值函數create function FUNC_Sum1( @a int , @b int)returns intasbegin return @a+@bend --新建內聯表值函數create function FUNC_UserTab_1( @myId int)returns tableasreturn ( select * from ST_User where ID<@myId) --新建多語句表值函數create function FUNC_UserTab_2( @myId int)returns @t table( [ID] [ int ] NOT NULL , [Oid] [ int ] NOT NULL , [Login] [nvarchar](50) NOT NULL , [Rtx] [nvarchar](4) NOT NULL , [ Name ] [nvarchar](5) NOT NULL , [ Password ] [nvarchar]( max ) NULL , [State] [nvarchar](8) NOT NULL)asbegin insert into @t select * from ST_User where ID<@myId returnend --調用表值函數select * from dbo.FUNC_UserTab_1(15)--調用標量值函數declare @s intset @s=dbo.FUNC_Sum1(100,50)print @s --刪除標量值函數drop function FUNC_Sum1
