--有輸入參數的存儲過程-- create proc GetComment (@commentid int) as select * 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 output as select @count=count(*) from Comment where NewsID=@newsid --返回單個值的函數-- create function MyFunction (@newsid int) returns int as begin declare @count int select @count=count(*) from Comment where NewsID=@newsid return @count end --調用方法-- declare @count int exec @count=MyFunction 2 print @count --返回值為表的函數-- Create function GetFunctionTable (@newsid int) returns table as return (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 int set @a=5 print @a --使用select語句賦值 declare @user1 nvarchar(50) select @user1= '張三' print @user1 declare @user2 nvarchar(50) select @user2 = Name from ST_User where ID=1 print @user2 --使用update語句賦值 declare @user3 nvarchar(50) update ST_User set @user3 = Name where ID=1 print @user3
二、表、臨時表、表變量
--創建臨時表1 create 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 --查詢並聯合兩臨時表 select * from #DU_User2 where ID<3 union select * from #DU_User1 --刪除兩臨時表 drop table #DU_User1 drop 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 #t drop 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_User select * 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 int declare @ sum int set @a=1 set @ sum =0 while @a<=100 begin set @ sum +=@a set @a+=1 end print @ sum
四、條件語句
--if,else條件分支 if(1+1=2) begin print '對' end else begin print '錯' end --when then條件分支 declare @today int declare @week nvarchar(3) set @today=3 set @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' end print @week
五、游標
declare @ID int declare @Oid int declare @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_cur while @@fetch_status=0 begin --讀取游標 fetch next from user_cur into @ID,@Oid,@Login print @ID --print @Login end close user_cur --摧毀游標 deallocate user_cur
五、游標
declare @ID int declare @Oid int declare @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_cur while @@fetch_status=0 begin --讀取游標 fetch next from user_cur into @ID,@Oid,@Login print @ID --print @Login end close 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 操作後的數據
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 output AS BEGIN set @ sum =@a+@b END --創建Return返回值存儲過程 CREATE PROCEDURE PR_Sum2 @a int , @b int AS BEGIN Return @a+@b END --執行存儲過程獲取output型返回值 declare @mysum int execute PR_Sum 1,2,@mysum output print @mysum --執行存儲過程獲取Return型返回值 declare @mysum2 int execute @mysum2= PR_Sum2 1,2 print @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 int as begin return @a+@b end --新建內聯表值函數 create function FUNC_UserTab_1 ( @myId int ) returns table as return ( 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 ) as begin insert into @t select * from ST_User where ID<@myId return end --調用表值函數 select * from dbo.FUNC_UserTab_1(15) --調用標量值函數 declare @s int set @s=dbo.FUNC_Sum1(100,50) print @s --刪除標量值函數 drop function FUNC_Sum1