查询分页的几种Sql写法
Posted
tags:
篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了查询分页的几种Sql写法相关的知识，希望对你有一定的参考价值。
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 @[email protected]+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():
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 [email protected] 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 ‘[email protected]+‘ DESC ‘
34 ELSE SET @strOrder=‘ ORDER BY ‘[email protected]+‘ ASC ‘
35
36 SET @strSql=‘SELECT * FROM
37 (SELECT ROW_NUMBER() OVER(‘[email protected]+‘) 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
C#
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");
}
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];
}
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 + ‘‘[email protected]+‘)a)
‘[email protected]+‘‘
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
以上是关于查询分页的几种Sql写法的主要内容，如果未能解决你的问题，请参考以下文章