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 DBTest
use 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 int
set @i=0
while(@i<10000)
begin
    insert into pagetest select cast(floor(rand()*10000) as int),left(newid(),10),getdate()
    set @i=@i+1
end

　　

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/top
select top 50 * from pagetest 
where id not in (select top 9900 id from pagetest order by id)
order by id


--写法2，not exists
select 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/top
select top 50 * from pagetest
where 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)a
where rownumber>9900

select * from 
(select row_number()over(order by id)rownumber,* from pagetest)a
where rownumber>9900 and rownumber<9951

select * from 
(select row_number()over(order by id)rownumber,* from pagetest)a
where 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
)b
where 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 datetime
declare @end_date datetime
select @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 @TotalCount
END
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

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

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
as
declare @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 !=''
begin
set @strSqlCount='Select @TotalCout=count(*) from  ' + @tbName + ' where '+ @strWhere
end
else
begin
set @strSqlCount='Select @TotalCout=count(*) from  ' + @tbName
end
--------------分页------------
if @PageIndex <= 0
begin
  set @PageIndex = 1
end

set @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 output
exec(@strSql)

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