千万数量级分页存储过程-修正跨页查询的BUG

ALTER PROCEDURE [dbo].[sp_pager]
/*
***************************************************************
** 千万数量级分页存储过程 **
***************************************************************
参数说明:
1.Tables :表名称,视图
2.PrimaryKey :主关键字
3.Sort :排序语句，不带Order By 比如：NewsID Desc,OrderRows Asc
4.CurrentPage :当前页码
5.PageSize :分页尺寸
6.Filter :过滤语句，不带Where 
7.Group :Group语句,不带Group By
***************************************************************/

(
@Tables varchar(1000),
@PrimaryKey varchar(100),
@Sort varchar(200) = NULL,
@CurrentPage int = 1,
@PageSize int = 10,
@Fields varchar(1000) = '*',
@Filter varchar(1000) = NULL,
@Group varchar(1000) = NULL,
@RecordCount int OUTPUT 
)
AS
--默认排序
IF @Sort IS NULL OR @Sort = ''
SET @Sort = @PrimaryKey
DECLARE @SortTable varchar(100)
DECLARE @SortName varchar(100)
DECLARE @strSortColumn varchar(200)
DECLARE @operator char(2)
DECLARE @type varchar(100)
DECLARE @prec int
declare @str NVarchar(600) 

--设定排序语句
IF CHARINDEX('DESC',@Sort)>0
BEGIN
SET @strSortColumn = REPLACE(@Sort, 'DESC', '')
SET @operator = '<='
END
ELSE
BEGIN
IF CHARINDEX('ASC', @Sort) = 0
SET @strSortColumn = REPLACE(@Sort, 'ASC', '')
SET @operator = '>='
END
IF CHARINDEX('.', @strSortColumn) > 0
BEGIN
SET @SortTable = SUBSTRING(@strSortColumn, 0, CHARINDEX('.',@strSortColumn))
SET @SortName = SUBSTRING(@strSortColumn, CHARINDEX('.',@strSortColumn) + 1, LEN(@strSortColumn))
END
ELSE
BEGIN
SET @SortTable = @Tables
SET @SortName = @strSortColumn
END
SELECT @type=t.name, @prec=c.prec
FROM sysobjects o 
JOIN syscolumns c on o.id=c.id
JOIN systypes t on c.xusertype=t.xusertype
WHERE o.name = @SortTable AND c.name = @SortName
IF CHARINDEX('char', @type) > 0
SET @type = @type + '(' + CAST(@prec AS varchar) + ')'
DECLARE @strPageSize varchar(50)
DECLARE @strStartRow varchar(50)
DECLARE @strFilter varchar(1000)
DECLARE @strSimpleFilter varchar(1000)
DECLARE @strGroup varchar(1000)
--默认当前页
IF @CurrentPage < 1
SET @CurrentPage = 1
--设置分页参数
SET @strPageSize = CAST(@PageSize AS varchar(50))
SET @strStartRow = CAST(((@CurrentPage - 1)*@PageSize + 1) AS varchar(50))
--筛选以及分组语句
IF @Filter IS NOT NULL AND @Filter != ''
BEGIN
SET @strFilter = ' WHERE ' + @Filter + ' '
SET @strSimpleFilter = ' AND ' + @Filter + ' '
END
ELSE
BEGIN
SET @strSimpleFilter = ''
SET @strFilter = ''
END
IF @Group IS NOT NULL AND @Group != ''
SET @strGroup = ' GROUP BY ' + @Group + ' '
ELSE
SET @strGroup = ''
-- 执行查询语句

select @str=N'select @recordcount=count(*) from '+@Tables+ @strFilter
Execute sp_executesql @str,N'@recordcount int OUTPUT',@recordcount=@recordcount OUTPUT

DECLARE @SQL VARCHAR(MAX);

DECLARE @pageCount INT;
--@CurrentPage int = 1,@PageSize
SET @pageCount = CEILING((@recordcount+.0)/(@PageSize+.0));
--处理超页查询的BUG
IF(@pageCount<@CurrentPage)
BEGIN
	SET @SQL = 'select ' + @Fields + ' FROM ' + @Tables + ' WHERE 1=2';
END
ELSE
	BEGIN
		SET @SQL = '
DECLARE @SortColumn ' + @type + '
SET ROWCOUNT ' + @strStartRow + '
SELECT @SortColumn=' + @strSortColumn + ' FROM ' + @Tables + @strFilter + ' ' + @strGroup + ' ORDER BY ' + @Sort + '
SET ROWCOUNT ' + @strPageSize + '
SELECT ' + @Fields + ' FROM ' + @Tables + ' WHERE ' + @strSortColumn + @operator + ' @SortColumn ' + @strSimpleFilter + ' ' + @strGroup + ' ORDER BY ' + @Sort + '
';
	END

PRINT @SQL;

EXEC(@SQL)