查詢分頁的幾種Sql寫法


查詢分頁的幾種Sql寫法

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

 

 

1.創建測試環境,(插入100萬條數據大概耗時5分鍾)。

create database DBTest
use DBTest

--創建測試表
create table pagetest
(
id int identity(1,1) not null,
col01 int null,
col02 nvarchar(50) null,
col03 datetime null
)

--1萬記錄集
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.幾種典型的分頁sql,下面例子是每頁50條,198*50=9900,取第199頁數據。

--寫法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


--寫法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

--寫法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

--寫法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

--寫法5,在csdn上一帖子看到的,row_number() 變體,不基於已有字段產生記錄序號,先按條件篩選以及排好序,再在結果集上給一常量列用於產生記錄序號
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.分別在1萬,10萬(取1990頁),100(取19900頁)記錄集下測試。

測試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'

  

1萬:基本感覺不到差異。

10萬:

4.結論:

1.max/top,ROW_NUMBER()都是比較不錯的分頁方法。相比ROW_NUMBER()只支持sql2005及以上版本,max/top有更好的可移植性,能同時適用於sql2000,access。

2.not exists感覺是要比not in效率高一點點。

3.ROW_NUMBER()的3種不同寫法效率看起來差不多。

4.ROW_NUMBER() 的變體基於我這個測試效率實在不好。原帖在這里 http://topic.csdn.net/u/20100617/04/80d1bd99-2e1c-4083-ad87-72bf706cb536.html

 

PS.上面的分頁排序都是基於自增字段id。測試環境還提供了int,nvarchar,datetime類型字段,也可以試試。不過對於非主鍵沒索引的大數據量排序效率應該是很不理想的。

 

5.簡單將ROWNUMBER,max/top的方式封裝到存儲過程。

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,               --頁尺寸
    @PageIndex INT=1,               --頁碼
    @OrderType bit = 0,                --0升序,非0降序
    @strWhere VARCHAR(1000)='',     --查詢條件
    --@TotalCount INT OUTPUT            --返回總記錄數
)
AS
-- =============================================
-- Author:      allen (liyuxin)
-- Create date: 2012-03-30
-- Description: 分頁存儲過程(支持多表連接查詢)
-- Modify [1]:  2012-03-30
-- =============================================
BEGIN
    DECLARE @strSql VARCHAR(5000)    --主語句
    DECLARE @strSqlCount NVARCHAR(500)--查詢記錄總數主語句
    DECLARE @strOrder VARCHAR(300) -- 排序類型

    --------------總記錄數---------------
    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
    --------------分頁------------
    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
復制代碼
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>
        /// 分頁獲取數據列表及總行數
        /// </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">頁尺寸</param>
        /// <param name="PageIndex">頁碼</param>
        /// <param name="OrderType">false升序,true降序</param>
        /// <param name="strWhere">查詢條件</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");
        }


       
復制代碼
View Code

調用:

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];
        }
復制代碼
View Code

注意:多表連接時需注意的地方
1.必填項:tbName,OrderfldName,tbGetFields
2.實例: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:每個條件前必須添加 AND (例如:AND UserInfo.DepID=1 )
 

Max/top:(簡單寫了下,需要滿足主鍵字段名稱就是"id")

create proc [dbo].[spSqlPageByMaxTop]
@tbName varchar(255),        --表名
@tbFields varchar(1000),      --返回字段
@PageSize int,                --頁尺寸
@PageIndex int,                --頁碼
@strWhere varchar(1000),    --查詢條件
@StrOrder varchar(255),  --排序條件
@Total int output            --返回總記錄數
as
declare @strSql varchar(5000)    --主語句
declare @strSqlCount nvarchar(500)--查詢記錄總數主語句

--------------總記錄數---------------
if @strWhere !=''
begin
set @strSqlCount='Select @TotalCout=count(*) from  ' + @tbName + ' where '+ @strWhere
end
else
begin
set @strSqlCount='Select @TotalCout=count(*) from  ' + @tbName
end
--------------分頁------------
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)
View Code

園子里搜到Max/top這么一個版本,看起來很強大,http://www.cnblogs.com/hertcloud/archive/2005/12/21/301327.html

調用:

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

  


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