使用 OUTPUT 参数
OUTPUT 参数允许外部过程、批处理或多条 Transact-SQL 语句访问在过程执行期间设置的某个值。下面的示例创建一个存储过程 (titles_sum),并使用一个可选的输入参数和一个输出参数。首先,创建过程:USE pubs
GO
IF EXISTS(SELECT name FROM sysobjects
WHERE name = 'titles_sum' AND type = 'P')
DROP PROCEDURE titles_sum
GO
USE pubs
GO
CREATE PROCEDURE titles_sum @@TITLE varchar(40) = '%', @@SUM money OUTPUT
AS
SELECT 'Title Name' = title
FROM titles
WHERE title LIKE @@TITLE
SELECT @@SUM = SUM(price)
FROM titles
WHERE title LIKE @@TITLE
GO
OUTPUT 参数允许外部过程、批处理或多条 Transact-SQL 语句访问在过程执行期间设置的某个值。下面的示例创建一个存储过程 (titles_sum),并使用一个可选的输入参数和一个输出参数。首先,创建过程:USE pubs
GO
IF EXISTS(SELECT name FROM sysobjects
WHERE name = 'titles_sum' AND type = 'P')
DROP PROCEDURE titles_sum
GO
USE pubs
GO
CREATE PROCEDURE titles_sum @@TITLE varchar(40) = '%', @@SUM money OUTPUT
AS
SELECT 'Title Name' = title
FROM titles
WHERE title LIKE @@TITLE
SELECT @@SUM = SUM(price)
FROM titles
WHERE title LIKE @@TITLE
GO
参数名和变量名不一定要匹配,不过数据类型和参数位置必须匹配(除非使用 @@SUM = variable 形式)。 DECLARE @@TOTALCOST money
EXECUTE titles_sum 'The%', @@TOTALCOST OUTPUT
IF @@TOTALCOST < 200
BEGIN
PRINT ' '
PRINT 'All of these titles can be purchased for less than $200.'
END
ELSE
SELECT 'The total cost of these titles is $'
+ RTRIM(CAST(@@TOTALCOST AS varchar(20)))下面是结果集:Title Name
------------------------------------------------------------------------
The Busy Executive's Database Guide
The Gourmet Microwave
The Psychology of Computer Cooking(3 row(s) affected)Warning, null value eliminated from aggregate.
All of these titles can be purchased for less than $200.是联机帮助的例子给个简单的例子
create proc Test
@Flag varchar(10) output
as
select @flag="成功"
go
执行的步骤
declare @str nvarchar(10)
exec test @Str=@flag outout
select @str
EXEC @MinPostID = dbo.msp_ExecuteSql(@MinTopID)
select @MinPostID 試試?
EXEC @MinPostID = dbo.msp_ExecuteSql(@MinTopID)
select @MinPostID 試試?
EXEC @MinPostID = dbo.msp_ExecuteSql(@MinTopID)
select @MinPostID 試試?
EXEC @MinPostID = dbo.msp_ExecuteSql(@MinTopID)
select @MinPostID 讀取的是存儲過程中的return的值,如果寫存儲過程時沒顯示使用 return(n),隻要存儲過程運行成功,它自己會返回0測試:create proc p1 as
print 1
go
create proc p2 as
print 1
return(8)
go
declare @A int
exec @A=p1
select @A as '返回值'--返回0declare @A int
exec @A=p2
select @A as '返回值'
--返回8
EXEC @MinPostID = dbo.msp_ExecuteSql(@MinTopID)
select @MinPostID 讀取的是存儲過程中的return的值,如果寫存儲過程時沒顯示使用 return(n),隻要存儲過程運行成功,它自己會返回0測試:create proc p1 as
print 1
go
create proc p2 as
print 1
return(8)
go
declare @A int
exec @A=p1
select @A as '返回值'--返回0declare @A int
exec @A=p2
select @A as '返回值'
--返回8
还是有错误,
EXEC @MinPostID = dbo.msp_ExecuteSql(@MinTopID)
select @MinPostID
执行后'@MinTopID' 附近有语法错误。
@MinTopID int,
@MinPostID int OUTPUT
ASBEGIN
Declare @strSql nvarchar(1000)
Select @strSql = 'Select '+@MinPostID+' = Min(PostID) From (Select Top '+@MinTopID+' PostID From ForumThreads Order By PostID Desc ) As Forum'
Exec(@strSql)
END