你的位置:首页 > 数据库

[数据库]查询分页的几种Sql写法


查询分页的几种Sql写法

摘自:http://www.cnblogs.com/zcttxs/archive/2012/04/01/2429151.html

 

 

1.创建测试环境,(插入100万条数据大概耗时5分钟)。

create database DBTestuse DBTest--创建测试表create table pagetest(id int identity(1,1) not null,col01 int null,col02 nvarchar(50) null,col03 datetime null)--1万记录集declare @i intset @i=0while(@i<10000)begin  insert into pagetest select cast(floor(rand()*10000) as int),left(newid(),10),getdate()  set @i=@i+1end

  

2.几种典型的分页sql,下面例子是每页50条,198*50=9900,取第199页数据。

--写法1,not in/topselect top 50 * from pagetest where id not in (select top 9900 id from pagetest order by id)order by id--写法2,not existsselect top 50 * from pagetest where not exists (select 1 from (select top 9900 id from pagetest order by id)a where a.id=pagetest.id)order by id--写法3,max/topselect top 50 * from pagetestwhere id>(select max(id) from (select top 9900 id from pagetest order by id)a)order by id--写法4,row_number()select top 50 * from (select row_number()over(order by id)rownumber,* from pagetest)awhere rownumber>9900select * from (select row_number()over(order by id)rownumber,* from pagetest)awhere rownumber>9900 and rownumber<9951select * from (select row_number()over(order by id)rownumber,* from pagetest)awhere rownumber between 9901 and 9950--写法5,在csdn上一帖子看到的,row_number() 变体,不基于已有字段产生记录序号,先按条件筛选以及排好序,再在结果集上给一常量列用于产生记录序号select *from (  select row_number()over(order by tempColumn)rownumber,*  from (select top 9950 tempColumn=0,* from pagetest where 1=1 order by id)a)bwhere rownumber>9900

  

3.分别在1万,10万(取1990页),100(取19900页)记录集下测试。

测试sql:

declare @begin_date datetimedeclare @end_date datetimeselect @begin_date = getdate()<.....YOUR CODE.....>select @end_date = getdate()select datediff(ms,@begin_date,@end_date) as '毫秒'

  

1万:基本感觉不到差异。

10万:

4.结论:

1.max/top,ROW_NUMBER()都是比较不错的分页方法。相比ROW_NUMBER()只支持sql2005及以上版本,max/top有更好的可移植性,能同时适用于sql2000,access。

2.not exists感觉是要比not in效率高一点点。

3.ROW_NUMBER()的3种不同写法效率看起来差不多。

4.ROW_NUMBER() 的变体基于我这个测试效率实在不好。原帖在这里 http://topic.csdn.net/u/20100617/04/80d1bd99-2e1c-4083-ad87-72bf706cb536.html

 

PS.上面的分页排序都是基于自增字段id。测试环境还提供了int,nvarchar,datetime类型字段,也可以试试。不过对于非主键没索引的大数据量排序效率应该是很不理想的。

 

5.简单将ROWNUMBER,max/top的方式封装到存储过程。

ROWNUMBER():

ALTER PROCEDURE [dbo].[Proc_SqlPageByRownumber](  @tbName VARCHAR(255),      --表名  @tbGetFields VARCHAR(1000)= '*',--返回字段  @OrderfldName VARCHAR(255),    --排序的字段名  @PageSize INT=20,        --页尺寸  @PageIndex INT=1,        --页码  @OrderType bit = 0,        --0升序,非0降序  @strWhere VARCHAR(1000)='',   --查询条件  --@TotalCount INT OUTPUT      --返回总记录数)AS-- =============================================-- Author:   allen (liyuxin)-- Create date: 2012-03-30-- Description: 分页存储过程(支持多表连接查询)-- Modify [1]: 2012-03-30-- =============================================BEGIN  DECLARE @strSql VARCHAR(5000)  --主语句  DECLARE @strSqlCount NVARCHAR(500)--查询记录总数主语句  DECLARE @strOrder VARCHAR(300) -- 排序类型  --------------总记录数---------------  IF ISNULL(@strWhere,'') <>''     SET @strSqlCount='Select @TotalCout=count(*) from ' + @tbName + ' where 1=1 '+ @strWhere  ELSE SET @strSqlCount='Select @TotalCout=count(*) from ' + @tbName    --exec sp_executesql @strSqlCount,N'@TotalCout int output',@TotalCount output  --------------分页------------  IF @PageIndex <= 0 SET @PageIndex = 1  IF(@OrderType<>0) SET @strOrder=' ORDER BY '+@OrderfldName+' DESC '  ELSE SET @strOrder=' ORDER BY '+@OrderfldName+' ASC '  SET @strSql='SELECT * FROM   (SELECT ROW_NUMBER() OVER('+@strOrder+') RowNo,'+ @tbGetFields+' FROM ' + @tbName + ' WHERE 1=1 ' + @strWhere+' ) tb   WHERE tb.RowNo BETWEEN '+str((@PageIndex-1)*@PageSize+1)+' AND ' +str(@PageIndex*@PageSize)  exec(@strSql)  SELECT @TotalCountEND复制代码

public static SqlParameter MakeInParam(string ParamName, SqlDbType DbType, Int32 Size, object Value)    {      return MakeParam(ParamName, DbType,Size, ParameterDirection.Input, Value);    }    public static SqlParameter MakeOutParam(string ParamName, SqlDbType DbType)    {      return MakeParam(ParamName, DbType, 0, ParameterDirection.Output, null);    }    public static SqlParameter MakeParam(string ParamName, SqlDbType DbType, Int32 Size, ParameterDirection Direction, object Value)    {      SqlParameter param;      if (Size > 0)        param = new SqlParameter(ParamName, DbType, Size);      else        param = new SqlParameter(ParamName, DbType);      param.Direction = Direction;      if (!(Direction == ParameterDirection.Output && Value == null))        param.Value = Value;      return param;    }    /// <summary>    /// 分页获取数据列表及总行数    /// </summary>    /// <param name="tbName">表名</param>    /// <param name="tbGetFields">返回字段</param>    /// <param name="OrderFldName">排序的字段名</param>    /// <param name="PageSize">页尺寸</param>    /// <param name="PageIndex">页码</param>    /// <param name="OrderType">false升序,true降序</param>    /// <param name="strWhere">查询条件</param>    public static DataSet GetPageList(string tbName, string tbGetFields, string OrderFldName, int PageSize, int PageIndex, string strWhere)    {      SqlParameter[] parameters = {            MakeInParam("@tbName",SqlDbType.VarChar,255,tbName),            MakeInParam("@tbGetFields",SqlDbType.VarChar,1000,tbGetFields),             MakeInParam("@OrderfldName",SqlDbType.VarChar,255,OrderFldName),             MakeInParam("@PageSize",SqlDbType.Int,0,PageSize),             MakeInParam("@PageIndex",SqlDbType.Int,0,PageIndex),             MakeInParam("@OrderType",SqlDbType.Bit,0,OrderType),             MakeInParam("@strWhere",SqlDbType.VarChar,1000,strWhere),            // MakeOutParam("@TotalCount",SqlDbType.Int)            };      return RunProcedure("Proc_SqlPageByRownumber", parameters, "ds");    }    复制代码

View Code

调用:

public DataTable GetList(string tbName, string tbGetFields, string OrderFldName, int PageSize, int PageIndex, string strWhere, ref int TotalCount)    {      DataSet ds = dal.GetList(tbName, tbGetFields, OrderFldName, PageSize, PageIndex, strWhere);      TotalCount = Convert.ToInt32(ds.Tables[1].Rows[0][0]);      return ds.Tables[0];    }复制代码

View Code

注意:多表连接时需注意的地方
1.必填项:tbName,OrderfldName,tbGetFields
2.实例:tbName =“UserInfo u INNER JOIN Department d ON u.DepID=d.ID”
        tbGetFields=“u.ID AS UserID,u.Name,u.Sex,d.ID AS DepID,d.DefName”
        OrderfldName=“u.ID,ASC|u.Name,DESC” (格式:Name,ASC|ID,DESC)
        strWhere:每个条件前必须添加 AND (例如:AND UserInfo.DepID=1 )
 

Max/top:(简单写了下,需要满足主键字段名称就是"id")

create proc [dbo].[spSqlPageByMaxTop]@tbName varchar(255),    --表名@tbFields varchar(1000),   --返回字段@PageSize int,        --页尺寸@PageIndex int,        --页码@strWhere varchar(1000),  --查询条件@StrOrder varchar(255), --排序条件@Total int output      --返回总记录数asdeclare @strSql varchar(5000)  --主语句declare @strSqlCount nvarchar(500)--查询记录总数主语句--------------总记录数---------------if @strWhere !=''beginset @strSqlCount='Select @TotalCout=count(*) from ' + @tbName + ' where '+ @strWhereendelsebeginset @strSqlCount='Select @TotalCout=count(*) from ' + @tbNameend--------------分页------------if @PageIndex <= 0begin set @PageIndex = 1endset @strSql='select top '+str(@PageSize)+' * from ' + @tbName + 'where id>(select max(id) from (select top '+str((@PageIndex-1)*@PageSize)+' id from ' + @tbName + ''+@strOrder+')a)'+@strOrder+''exec sp_executesql @strSqlCount,N'@TotalCout int output',@Total outputexec(@strSql)

View Code

园子里搜到Max/top这么一个版本,看起来很强大,http://www.cnblogs.com/hertcloud/archive/2005/12/21/301327.html

调用:

declare @count int--exec [dbo].[spSqlPageByRownumber]'pagetest','*',50,20,'','order by id asc',@count output exec [dbo].[spSqlPageByMaxTop]'pagetest','*',50,20,'','order by id asc',@count output select @count