sql错误 帮忙看看

[挨踢直男]

DECLARE @X INT
SET @X = 2
SELECT TOP @X * FROM USER_INFO


这样写是错的

怎么样写才是正确的啊

[htl258_Tony]

2005

DECLARE @X INT  
SET @X = 2
SELECT TOP (@X) * FROM USER_INFO

[-狙击手-]

2000


DECLARE @X INT
SET @X = 2
exec('SELECT TOP '+ltrim(@X)+' * FROM USER_INFO')

[htl258_Tony]

2000

DECLARE @X VARCHAR(10)  
SET @X = 2
EXEC('SELECT TOP '+@X+' * FROM USER_INFO')

[dawugui]

/*
在TOP后面使用变量
(爱新觉罗.毓华(十八年风雨,守得冰山雪莲花开)  2008-01-02  广东深圳)
*/

--SQL SERVER 2005 的写法
use adventureworks
go

DECLARE @Percentage int
SET @Percentage = 1
SELECT TOP (@Percentage) PERCENT
Name
FROM Production.Product
ORDER BY Name

/*
Name
----------------------
Adjustable Race
All-Purpose Bike Stand
AWC Logo Cap
BB Ball Bearing
Bearing Ball
Bike Wash - Dissolver

(6 行受影响)
*/

-----------------------------------
--SQL SERVER 2000 的写法
create table a([id] [int])
insert into a(id) values(1)
insert into a(id) values(2)
insert into a(id) values(3)
insert into a(id) values(4)
insert into a(id) values(5)

declare @num as int
declare @sql as varchar(2000)
set @num = 2
set @sql = 'select top ' + cast(@num as char) + ' * from a'
exec(@sql)

drop table a
/*
id          
----------- 
1
2
*/

[htl258_Tony]

OR

DECLARE @X INT,@s varchar(1000)   
SET @X = 2
SET @s='SELECT TOP '+ltrim(@X)+' * FROM USER_INFO'
EXEC(@S)

[dawugui]

--sql 2000

DECLARE @X INT  
SET @X = 2

exec('SELECT TOP ' + ltrim(@X) + ' * FROM USER_INFO')

--sql 2005

DECLARE @X INT  
SET @X = 2
SELECT TOP (@X) * FROM USER_INFO

[心中的彩虹]

--多多动手,相互提升
IF NOT OBJECT_ID('[tb]') IS NULL
    DROP TABLE [tb]
GO
CREATE TABLE [tb]([name] NVARCHAR(10),[sex] INT)
INSERT [tb]
SELECT 'ga',1 UNION ALL
SELECT 'de',0 UNION ALL
SELECT 'ff',1 UNION ALL
SELECT 'hh',1 UNION ALL
SELECT 'kk',0
GO

DECLARE @X INT,@sql varchar(1000)
SET @X = 2
set @sql='SELECT TOP '+cast(@X as varchar(2))+'* FROM tb '
select @sql      --结果为"SELECT TOP 2* FROM tb "
exec(@sql)

--结果为
name    sex
ga	1
de	0

[lovehong123]

热烈欢迎.NET程序员加入108860028群,我们共同进步,追逐各自的梦想!