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The author:(作者)归海一刀
published in(发表于) 2014/2/3 6:46:05
数据库的分页问题_[SQL Server教程]

create proc up_PageView
(
@tableName sysname,
@colKey nvarchar(100),
@pageCurrent int = 1,
@pageSize int = 10,
@colShow nvarchar(4000) = '',
@colOrder nvarchar(200) = '',
@where nvarchar(2000) = '',
@pageCount int output
)
as
begin
if object_id(@tableName) is null
begin
raiserror('the table is not existing!', 16,1)
return
end
if isnull(@colShow, '') = ''
set @colShow = '*'
if isnull(@colOrder,'') = ''
set @colOrder = ''
else
set @colOrder = 'order by ' + @colOrder
if isnull(@where, '') = ''
set @where = ''
else
set @where = 'where '+ @where
declare @sql nvarchar(4000)
if @pageCount is null
begin
set @sql = 'select @pageCount = count(*) from ' + @tableName + ' ' + @where
Exec sp_executesql @sql, '@pageCount int output', @pageCount output
set @pageCount = (@pageCount + @pageSize -1)/@pageSize
end
if @pageCurrent = 1
set @sql = 'select top' +' ' + convert(nvarchar(10), @pageSize) + ' '
+ @colshow + ' ' + 'from ' + @tableName + ' ' + @where + ' ' + @colOrder
else
begin
set @sql = 'select top' +' ' + convert(nvarchar(10), @pageSize) + ' '
+ @colshow + ' ' + 'from ' + @tableName + ' ' + @where
set @sql = @sql + ' ' + 'and '+ @colKey +' not in ( '
+ 'select top' +' ' + convert(nvarchar(10), (@pageCurrent - 1) * @pageSize) + ' '
+ @colKey + ' ' + 'from ' + @tableName + ' ' + @where + ' )'
set @sql = @sql + ' ' + @colOrder
end
--execute the dynamic query
exec (@sql)
end

这种方法的缺点是为了排除该页以前的页， 必须使用top n取大量的数据并缓存起来，在关联元表查询出最终结果，这样做的效率比较低。通常情况下， 我们都是对单主健（使用单个字段定位纪录）的表进行分页查询。因此，如果能使用一个字符串变量纪录指定页的所有主健，在使用in子句配合纪录的指定页主健就可以查询出最终的结果来。下面是改进的存储过程：

create proc up_PageView
(
@tableName sysname,
@colKey nvarchar(100),
@pageCurrent int = 1,
@pageSize int = 10,
@colShow nvarchar(4000) = '',
@colOrder nvarchar(200) = '',
@where nvarchar(2000) = '',
@pageCount int output
)
as
begin
if object_id(@tableName) is null
begin
raiserror('the table is not existing!', 16,1)
return
end
if isnull(@colShow, '') = ''
set @colShow = '*'
if isnull(@colOrder,'') = ''
set @colOrder = ''
else
set @colOrder = 'order by ' + @colOrder
if isnull(@where, '') = ''
set @where = ''
else
set @where = 'where '+ @where
declare @sql nvarchar(4000)
if @pageCount is null
begin
set @sql = 'select @pageCount = count(*) from ' + @tableName + ' ' + @where
Exec sp_executesql @sql, '@pageCount int output', @pageCount output
set @pageCount = (@pageCount + @pageSize -1)/@pageSize -- get total pages
end
if @pageCurrent = 1
begin
set @sql = N'select top' +N' ' + convert(nvarchar(10), @pageSize) + N' '
+ @colshow + N' ' + N'from ' + @tableName + N' ' + @where + N' ' + @colOrder
exec (@sql)
end
else
begin
declare @topN int, @topN1 int
-- set @topN = @pageSize
-- set @topN1 = @pageCurrent * @pageSize
set @pageCurrent = @pageCurrent * @pageSize
set @sql = N'select @n = @n - 1, @s = case when @n < ' + convert(nvarchar(10), @pageSize) +
N' then @s + '','' + quotename(@colKey, N'''''''') ' + N'else ''''' + N' end '
+ N' from '+ @tableName + N' ' + @where
--make query effect only @pageCurrent records
--Query only top @pageCurrent * @pageSize
set rowcount @pageCurrent
exec sp_executesql @sql, '@n int, @s nvarchar(max) output', @pageCurrent, @sql output
set rowcount 0 --recover to default config
set @sql = stuff(@sql, 1, 1, N'') -- remove the first ','
--exec the query
Exec (N'select ' + @colShow + N' ' + 'from' + N' ' + @tableName + N' '
+ N'where ' + @colKey + N' in (' + @sql + ')' + @colOrder)
end
end
go

另外， sql server 2005 增加了一些新的功能如取得排名或顺序的函数（Rank(), Dense_Rank(), Row_Number()）, 利用这些新的功能也能进行分页处理，下面以sql server 2005 自带的数据库AdventureWorks为例结合Row_Number() 实现分页处理：

create proc up_GetPagen
(
@pageSize int,
@pageCurrent int
)
as
begin
select * from
(select ROW_NUMBER() over(ORDER BY productid) RowNum, * from production.product )OrderData
where RowNum between (@pageCurrent - 1)*@pageSize + 1 and @pageCurrent * @pageSize
order by productid
end

不尽如此，这种新功能有许多妙用， 如可以取班级排名前N名或第n名到第m名的学生等等，这类问题将会在我以后的文章中进行讨论！
这是我的第一篇博客， 呵呵，处来砸到，讨论的问题希望对大家有所帮助，另外，如有疑难或错误之处，敬请指出！

http://www.cnblogs.com/alanding/archive/2007/02/02/638197.html

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