分页查询

/*--用存储过程实现的分页程序

 显示指定表、视图、查询结果的第X页
 对于表中主键或标识列的情况,直接从原表取数查询，其它情况使用临时表的方法
 如果视图或查询结果中有主键,不推荐此方法

--*/

/*--调用示例
 exec p_show '地区资料'

 exec p_show '地区资料',5,3,'地区编号,地区名称,助记码','地区编号'
--*/

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[p_show]') and OBJECTPROPERTY(id, N'IsProcedure') = 1)
drop procedure [dbo].[p_show]
GO

CREATE Proc p_show
@QueryStr nvarchar(4000), --表名、视图名、查询语句
@PageSize int=10,   --每页的大小(行数)
@PageCurrent int=1,   --要显示的页
@FdShow nvarchar (4000)='', --要显示的字段列表,如果查询结果有标识字段,需要指定此值,且不包含标识字段
@FdOrder nvarchar (1000)='' --排序字段列表
as
declare @FdName nvarchar(250) --表中的主键或表、临时表中的标识列名
 ,@Id1 varchar(20),@Id2 varchar(20) --开始和结束的记录号
 ,@Obj_ID int    --对象ID
--表中有复合主键的处理
declare @strfd nvarchar(2000) --复合主键列表
 ,@strjoin nvarchar(4000) --连接字段
 ,@strwhere nvarchar(2000) --查询条件

select @Obj_ID=object_id(@QueryStr)
 ,@FdShow=case isnull(@FdShow,'') when '' then ' *' else ' '+@FdShow end
 ,@FdOrder=case isnull(@FdOrder,'') when '' then '' else ' order by '+@FdOrder end
 ,@QueryStr=case when @Obj_ID is not null then ' '+@QueryStr else ' ('+@QueryStr+') a' end

--如果显示第一页，可以直接用top来完成
if @PageCurrent=1 
begin
 select @Id1=cast(@PageSize as varchar(20))
 exec('select top '+@Id1+@FdShow+' from '+@QueryStr+@FdOrder)
 return
end

--如果是表,则检查表中是否有标识更或主键
if @Obj_ID is not null and objectproperty(@Obj_ID,'IsTable')=1
begin
 select @Id1=cast(@PageSize as varchar(20))
  ,@Id2=cast((@PageCurrent-1)*@PageSize as varchar(20))

 select @FdName=name from syscolumns where id=@Obj_ID and status=0x80
 if @@rowcount=0   --如果表中无标识列,则检查表中是否有主键
 begin
  if not exists(select 1 from sysobjects where parent_obj=@Obj_ID and xtype='PK')
   goto lbusetemp  --如果表中无主键,则用临时表处理

  select @FdName=name from syscolumns where id=@Obj_ID and colid in(
   select colid from sysindexkeys where @Obj_ID=id and indid in(
    select indid from sysindexes where @Obj_ID=id and name in(
     select name from sysobjects where xtype='PK' and parent_obj=@Obj_ID
   )))
  if @@rowcount>1  --检查表中的主键是否为复合主键
  begin
   select @strfd='',@strjoin='',@strwhere=''
   select @strfd=@strfd+',['+name+']'
    ,@strjoin=@strjoin+' and a.['+name+']=b.['+name+']'
    ,@strwhere=@strwhere+' and b.['+name+'] is null'
    from syscolumns where id=@Obj_ID and colid in(
    select colid from sysindexkeys where @Obj_ID=id and indid in(
     select indid from sysindexes where @Obj_ID=id and name in(
      select name from sysobjects where xtype='PK' and parent_obj=@Obj_ID
    )))
   select @strfd=substring(@strfd,2,2000)
    ,@strjoin=substring(@strjoin,5,4000)
    ,@strwhere=substring(@strwhere,5,4000)
   goto lbusepk
  end
 end
end
else
 goto lbusetemp

/*--使用标识列或主键为单一字段的处理方法--*/
lbuseidentity: 
 exec('select top '+@Id1+@FdShow+' from '+@QueryStr
  +' where '+@FdName+' not in(select top '
  +@Id2+' '+@FdName+' from '+@QueryStr+@FdOrder
  +')'+@FdOrder
  )
 return

/*--表中有复合主键的处理方法--*/
lbusepk:  
 exec('select '+@FdShow+' from(select top '+@Id1+' a.* from
  (select top 100 percent * from '+@QueryStr+@FdOrder+') a
  left join (select top '+@Id2+' '+@strfd+'
  from '+@QueryStr+@FdOrder+') b on '+@strjoin+'
  where '+@strwhere+') a'
  )
 return

/*--用临时表处理的方法--*/
lbusetemp:  
select @FdName='[ID_'+cast(newid() as varchar(40))+']'
 ,@Id1=cast(@PageSize*(@PageCurrent-1) as varchar(20))
 ,@Id2=cast(@PageSize*@PageCurrent-1 as varchar(20))

exec('select '+@FdName+'=identity(int,0,1),'+@FdShow+'
  into #tb from'+@QueryStr+@FdOrder+'
 select '+@FdShow+' from #tb where '+@FdName+' between '
 +@Id1+' and '+@Id2
 )

GO