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分鐘)。
create database DBTestuse 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 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.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/topselect top 50 * from pagetest where id not in (select top 9900 id from pagetest order by id)order by id--寫法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--寫法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--寫法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--寫法5,在csdn上一帖子看到的,row_number() 變體,不基于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于產生記錄序號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)bwhere 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 datetimedeclare @end_date datetimeselect @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,能同時適用于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() 的變體基于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于自增字段id。測試環境還提供了int,nvarchar,datetime類型字段,也可以試試。不過對于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 @TotalCountEND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,tbGetFields2.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")
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