需求：
实现一个简单的分页存储过程。不使用通用存储过程，不到万不得已不使用存储过程内的字符串拼接。
实现：
set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
go
CREATE PROCEDURE [dbo].[sp_QueryPage_User]
@Page int = 1,
@PageSize int = 10
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
select top @PageSize * from tbl_User
where (UserNativeId not in (select top @[email protected] UserNativeId from tbl_User order by UserNativeId))
order by UserNativeId
END
go
错误提示：
Msg 102, Level 15, State 1, Procedure sp_QueryPage_User, Line 15
Incorrect syntax near '@PageSize '.
Msg 102, Level 15, State 1, Procedure sp_QueryPage_User, Line 16
Incorrect syntax near '@Page '.
分析： 将变量替换为常量后可以通过
例如将
select top @PageSize * from tbl_User
where (UserNativeId not in (select top @[email protected] UserNativeId from tbl_User order by UserNativeId))
order by UserNativeId
替换为
select top 10 * from tbl_User
where (UserNativeId not in (select top 30 UserNativeId from tbl_User order by UserNativeId))
order by UserNativeId
求解： select top 后面不能跟变量？还是有什么别的语法可以通过的？
------解决方案--------------------
declare @int int
set @int =1
exec( 'select top '[email protected]+ ' form sysobjects ')
------解决方案--------------------
CREATE PROCEDURE [dbo].[sp_QueryPage_User]
@Page int = 1,
@PageSize int = 10
AS
declare @sql varchar(1000)
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
set @sql= '
select top '[email protected]+ ' * from tbl_User
where (UserNativeId not in (select top '[email protected][email protected]+ ' UserNativeId from tbl_User order by UserNativeId))
order by UserNativeId '
exec(@sql)
END
go
------解决方案--------------------
declare @num int
select @num = 10
exec( 'select top '[email protected]+ ' * from sysobjects ')
------解决方案--------------------
用动态SQL语句。
动态sql语句基本语法
1 :普通SQL语句可以用Exec执行
eg: Select * from tableName
Exec( 'select * from tableName ')
Exec sp_executesql N 'select * from tableName ' -- 请注意字符串前一定要加N
2:字段名，表名，数据库名之类作为变量时，必须用动态SQL
eg:
declare @fname varchar(20)
set @fname = 'FiledName '
Select @fname from tableName -- 错误,不会提示错误，但结果为固定值FiledName,并非所要。
Exec( 'select ' + @fname + ' from tableName ') -- 请注意 加号前后的 单引号的边上加空格