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  • 查询分页的几种Sql写法

    1.创建测试环境,(插入100万条数据大概耗时5分钟)。

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    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
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    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。

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

    测试sql:

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    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'
     
     
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    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():

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     1 ALTER PROCEDURE [dbo].[Proc_SqlPageByRownumber]
    2 (
    3 @tbName VARCHAR(255), --表名
    4 @tbGetFields VARCHAR(1000)= '*',--返回字段
    5 @OrderfldName VARCHAR(255), --排序的字段名
    6 @PageSize INT=20, --页尺寸
    7 @PageIndex INT=1, --页码
    8 @OrderType bit = 0, --0升序,非0降序
    9 @strWhere VARCHAR(1000)='', --查询条件
    10 --@TotalCount INT OUTPUT --返回总记录数
    11 )
    12 AS
    13 -- =============================================
    14 -- Author: allen (liyuxin)
    15 -- Create date: 2012-03-30
    16 -- Description: 分页存储过程(支持多表连接查询)
    17 -- Modify [1]: 2012-03-30
    18 -- =============================================
    19 BEGIN
    20 DECLARE @strSql VARCHAR(5000) --主语句
    21 DECLARE @strSqlCount NVARCHAR(500)--查询记录总数主语句
    22 DECLARE @strOrder VARCHAR(300) -- 排序类型
    23
    24 --------------总记录数---------------
    25 IF ISNULL(@strWhere,'') <>''
    26 SET @strSqlCount='Select @TotalCout=count(*) from ' + @tbName + ' where 1=1 '+ @strWhere
    27 ELSE SET @strSqlCount='Select @TotalCout=count(*) from ' + @tbName
    28
    29 --exec sp_executesql @strSqlCount,N'@TotalCout int output',@TotalCount output
    30 --------------分页------------
    31 IF @PageIndex <= 0 SET @PageIndex = 1
    32
    33 IF(@OrderType<>0) SET @strOrder=' ORDER BY '+@OrderfldName+' DESC '
    34 ELSE SET @strOrder=' ORDER BY '+@OrderfldName+' ASC '
    35
    36 SET @strSql='SELECT * FROM
    37 (SELECT ROW_NUMBER() OVER('+@strOrder+') RowNo,'+ @tbGetFields+' FROM ' + @tbName + ' WHERE 1=1 ' + @strWhere+' ) tb
    38 WHERE tb.RowNo BETWEEN '+str((@PageIndex-1)*@PageSize+1)+' AND ' +str(@PageIndex*@PageSize)
    39
    40 exec(@strSql)
    41 SELECT @TotalCount
    42 END
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    C#

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     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");
    }


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    调用:

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     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];
    }
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    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")

    复制代码
    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)
     
     
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    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
     
    分类: SQLServer
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  • 原文地址:https://www.cnblogs.com/xiaofengfeng/p/2810480.html
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