weiqt

有关分页 SQL 的资料很多,有的使用存储过程,有的使用游标。本人不喜欢使用游标,我觉得它耗资、效率低;使用存储过程是个不错的选择,因为存储过程是经过预编译的,执行效率高,也更灵活。先看看单条 SQL 语句的分页 SQL 吧。其它的方案:如果没有主键,可以用临时表,也可以用方案三做,但是效率会低。

方法1:
适用于 SQL Server 2000/2005

SELECT TOP 页大小 *
FROM table1
WHERE id NOT IN
(
SELECT TOP 页大小*(页数-1) id FROM table1 ORDER BY id
)
ORDER BY id

方法2:
适用于 SQL Server 2000/2005

SELECT TOP 页大小 *
FROM table1
WHERE id >
(
SELECT ISNULL(MAX(id),0)
FROM
(
SELECT TOP 页大小*(页数-1) id FROM table1 ORDER BY id
) A
)
ORDER BY id

方法3:
适用于 SQL Server 2005

SELECT TOP 页大小 *
FROM
(
SELECT ROW_NUMBER() OVER (ORDER BY id) AS RowNumber,* FROM table1
) A
WHERE RowNumber > 页大小*(页数-1)

说明,页大小:每页的行数;页数:第几页。使用时,请把“页大小”和“页大小*(页数-1)”替换成数字。

建议优化的时候,加上主键和索引,查询效率会提高。

通过SQL 查询分析器,显示比较:我的结论是:
分页方案二:(利用ID大于多少和SELECT TOP分页)效率最高,需要拼接SQL语句
分页方案一:(利用Not In和SELECT TOP分页)   效率次之,需要拼接SQL语句
分页方案三:(利用SQL的游标存储过程分页)    效率最差,但是最为通用

///////////////////////////////////////////////////////////////////////////////////////////////////////

不同分页存储过程分析

OK,我们首先创建一数据库:data_Test,并在此数据库中创建一表:tb_TestTable


1
create database data_Test --创建数据库data_Test
2GO
3
use data_Test
4
GO
5
create table tb_TestTable --创建表
6(
7 id int identity(1,1) primary key,
8 userName nvarchar(20) not null,
9 userPWD nvarchar(20) not null,
10 userEmail nvarchar(40) null
11)
12
GO

然后我们在数据表中插入2000000条数据:

1--插入数据
2set identity_insert tb_TestTable on
3
declare @count int
4
set @count=1
5
while @count<=2000000
6
begin
7 insert into tb_TestTable(id,userName,userPWD,userEmail) values(@count,\'admin\',\'admin888\',\'lli0077@yahoo.com.cn\')
8 set @count=@count+1
9
end
10
set identity_insert tb_TestTable off

我首先写了五个常用存储过程:
1,利用select top 和select not in进行分页,具体代码如下:

1
create procedure proc_paged_with_notin --利用select top and select not in
2(
3 @pageIndex int, --页索引
4 @pageSize int --每页记录数
5)
6
as
7
begin
8 set nocount on;
9 declare @timediff datetime --耗时
10 declare @sql nvarchar(500)
11 select @timediff=Getdate()
12 set @sql=\'select top \'+str(@pageSize)+\' * from tb_TestTable where(ID not in(select top \'+str(@pageSize*@pageIndex)+\' id from tb_TestTable order by ID ASC)) order by ID\'
13 execute(@sql) --因select top后不支技直接接参数,所以写成了字符串@sql
14 select datediff(ms,@timediff,GetDate()) as 耗时
15 set nocount off;
16
end

2,利用select topselect max(列键)


1
create procedure proc_paged_with_selectMax --利用select top and select max(列)
2(
3 @pageIndex int, --页索引
4 @pageSize int --页记录数
5)
6
as
7
begin
8
set nocount on;
9 declare @timediff datetime
10 declare @sql nvarchar(500)
11 select @timediff=Getdate()
12 set @sql=\'select top \'+str(@pageSize)+\' * From tb_TestTable where(ID>(select max(id) From (select top \'+str(@pageSize*@pageIndex)+\' id From tb_TestTable order by ID) as TempTable)) order by ID\'
13 execute(@sql)
14 select datediff(ms,@timediff,GetDate()) as 耗时
15
set nocount off;
16
end

3,利用select top和中间变量--此方法因网上有人说效果最佳,所以贴出来一同测试

1
create procedure proc_paged_with_Midvar --利用ID>最大ID值和中间变量
2(
3 @pageIndex int,
4 @pageSize int
5)
6
as
7 declare @count int
8 declare @ID int
9 declare @timediff datetime
10 declare @sql nvarchar(500)
11
begin
12
set nocount on;
13 select @count=0,@ID=0,@timediff=getdate()
14 select @count=@count+1,@ID=case when @count<=@pageSize*@pageIndex then ID else @ID end from tb_testTable order by id
15 set @sql=\'select top \'+str(@pageSize)+\' * from tb_testTable where ID>\'+str(@ID)
16 execute(@sql)
17 select datediff(ms,@timediff,getdate()) as 耗时
18
set nocount off;
19
end
20

4,利用Row_number() 此方法为SQL server 2005中新的方法,利用Row_number()给数据行加上索引


1
create procedure proc_paged_with_Rownumber --利用SQL 2005中的Row_number()
2(
3 @pageIndex int,
4 @pageSize int
5)
6
as
7 declare @timediff datetime
8
begin
9
set nocount on;
10 select @timediff=getdate()
11 select * from (select *,Row_number() over(order by ID asc) as IDRank from tb_testTable) as IDWithRowNumber where IDRank>@pageSize*@pageIndex and IDRank<@pageSize*(@pageIndex+1)
12 select datediff(ms,@timediff,getdate()) as 耗时
13
set nocount off;
14
end
15
5,利用临时表及Row_number

1
create procedure proc_CTE --利用临时表及Row_number
2(
3 @pageIndex int, --页索引
4 @pageSize int --页记录数
5)
6
as
7 set nocount on;
8 declare @ctestr nvarchar(400)
9 declare @strSql nvarchar(400)
10 declare @datediff datetime
11
begin
12 select @datediff=GetDate()
13 set @ctestr=\'with Table_CTE as
14 (select ceiling((Row_number() over(order by ID ASC))/
\'+str(@pageSize)+\') as page_num,* from tb_TestTable)\';
15 set @strSql=@ctestr+\' select * From Table_CTE where page_num=\'+str(@pageIndex)
16
end
17 begin
18 execute sp_executesql @strSql
19 select datediff(ms,@datediff,GetDate())
20 set nocount off;
21 end
22

OK,至此,存储过程创建完毕,我们分别在每页10条数据的情况下在第2页,第1000页,第10000页,第100000页,第199999页进行测试,耗时单位:ms  每页测试5次取其平均值

存过 第2页耗时 第1000页耗时 第10000页耗时 第100000页耗时 第199999页耗时 效率排行
1用not in 0ms 16ms 47ms 475ms 953ms 3
2用select max 5ms 16ms 35ms 325ms 623ms 1
3中间变量 966ms 970ms 960ms 945ms 933ms 5
4row_number 0ms 0ms 34ms 365ms 710ms 2
4临时表 780ms 796ms 798ms 780ms 805ms 4

测试结果显示:select max >row_number>not in>临时表>中间变量

于是我对效率最高的select max方法用2分法进行了扩展,代码取自互联网,我修改了ASC排序时取不到值的BUG,测试结果:

2分法 156ms 156ms 180ms 470ms 156ms 1*

  

从测试结果来看,使用2分法确实可以提高效率并使效率更为稳定,我又增加了第159999页的测试,用时仅296ms,效果相当的不错!

下面是2分法使用select max的代码,已相当完善。

alter PROCEDURE proc_paged_2part_selectMax 
  6( 
  7@tblName     nvarchar(200),        ----要显示的表或多个表的连接 
  8@fldName     nvarchar(500) = \'*\',    ----要显示的字段列表 
  9@pageSize    int = 10,        ----每页显示的记录个数 
 10@page        int = 1,        ----要显示那一页的记录 
 11@fldSort    nvarchar(200) = null,    ----排序字段列表或条件 
 12@Sort        bit = 0,        ----排序方法,0为升序,1为降序(如果是多字段排列Sort指代最后一个排序字段的排列顺序(最后一个排序字段不加排序标记)--程序传参如:\' SortA Asc,SortB Desc,SortC \') 
 13@strCondition    nvarchar(1000) = null,    ----查询条件,不需where 
 14@ID        nvarchar(150),        ----主表的主键 
 15@Dist                 bit = 0,           ----是否添加查询字段的 DISTINCT 默认0不添加/1添加 
 16@pageCount    int = 1 output,            ----查询结果分页后的总页数 
 17@Counts    int = 1 output                ----查询到的记录数 
 18) 
 19AS 
 20SET NOCOUNT ON 
 21Declare @sqlTmp nvarchar(1000)        ----存放动态生成的SQL语句 
 22Declare @strTmp nvarchar(1000)        ----存放取得查询结果总数的查询语句 
 23Declare @strID     nvarchar(1000)        ----存放取得查询开头或结尾ID的查询语句 
 24
 25Declare @strSortType nvarchar(10)    ----数据排序规则A 
 26Declare @strFSortType nvarchar(10)    ----数据排序规则B 
 27
 28Declare @SqlSelect nvarchar(50)         ----对含有DISTINCT的查询进行SQL构造 
 29Declare @SqlCounts nvarchar(50)          ----对含有DISTINCT的总数查询进行SQL构造 
 30
 31declare @timediff datetime  --耗时测试时间差 
 32select @timediff=getdate() 
 33
 34if @Dist  = 0 
 35begin 
 36    set @SqlSelect = \'select \' 
 37    set @SqlCounts = \'Count(*)\' 
 38end 
 39else 
 40begin 
 41    set @SqlSelect = \'select distinct \' 
 42    set @SqlCounts = \'Count(DISTINCT \'+@ID+\')\' 
 43end 
 44
 45
 46if @Sort=0 
 47begin 
 48    set @strFSortType=\' ASC \' 
 49    set @strSortType=\' DESC \' 
 50end 
 51else 
 52begin 
 53    set @strFSortType=\' DESC \' 
 54    set @strSortType=\' ASC \' 
 55end 
 56
 57
 58
 59--------生成查询语句-------- 
 60--此处@strTmp为取得查询结果数量的语句 
 61if @strCondition is null or @strCondition=\'\'     --没有设置显示条件 
 62begin 
 63    set @sqlTmp =  @fldName + \' From \' + @tblName 
 64    set @strTmp = @SqlSelect+\' @Counts=\'+@SqlCounts+\' FROM \'+@tblName 
 65    set @strID = \' From \' + @tblName 
 66end 
 67else 
 68begin 
 69    set @sqlTmp = + @fldName + \'From \' + @tblName + \' where (1>0) \' + @strCondition 
 70    set @strTmp = @SqlSelect+\' @Counts=\'+@SqlCounts+\' FROM \'+@tblName + \' where (1>0) \' + @strCondition 
 71    set @strID = \' From \' + @tblName + \' where (1>0) \' + @strCondition 
 72end 
 73
 74----取得查询结果总数量----- 
 75exec sp_executesql @strTmp,N\'@Counts int out \',@Counts out 
 76declare @tmpCounts int 
 77if @Counts = 0 
 78    set @tmpCounts = 1 
 79else 
 80    set @tmpCounts = @Counts 
 81
 82    --取得分页总数 
 83    set @pageCount=(@tmpCounts+@pageSize-1)/@pageSize 
 84
 85    /**//**当前页大于总页数 取最后一页**/ 
 86    if @page>@pageCount 
 87        set @page=@pageCount 
 88
 89    --/*-----数据分页2分处理-------*/ 
 90    declare @pageIndex int --总数/页大小 
 91    declare @lastcount int --总数%页大小  
 92
 93    set @pageIndex = @tmpCounts/@pageSize 
 94    set @lastcount = @tmpCounts%@pageSize 
 95    if @lastcount > 0 
 96        set @pageIndex = @pageIndex + 1 
 97    else 
 98        set @lastcount = @pagesize 
 99
100    --//***显示分页 
101    if @strCondition is null or @strCondition=\'\'     --没有设置显示条件 
102    begin 
103        if @pageIndex<2 or @page<=@pageIndex / 2 + @pageIndex % 2   --前半部分数据处理 
104            begin  
105                if @page=1 
106                    set @strTmp=@SqlSelect+\' top \'+ CAST(@pageSize as VARCHAR(4))+\' \'+ @fldName+\' from \'+@tblName                         
107                        +\' order by \'+ @fldSort +\' \'+ @strFSortType 
108                else 
109                begin 
110                    if @Sort=1 
111                    begin                     
112                    set @strTmp=@SqlSelect+\' top \'+ CAST(@pageSize as VARCHAR(4))+\' \'+ @fldName+\' from \'+@tblName 
113                        +\' where \'+@ID+\' <(select min(\'+ @ID +\') from (\'+ @SqlSelect+\' top \'+ CAST(@pageSize*(@page-1) as Varchar(20)) +\' \'+ @ID +\' from \'+@tblName 
114                        +\' order by \'+ @fldSort +\' \'+ @strFSortType+\') AS TBMinID)\' 
115                        +\' order by \'+ @fldSort +\' \'+ @strFSortType 
116                    end 
117                    else 
118                    begin 
119                    set @strTmp=@SqlSelect+\' top \'+ CAST(@pageSize as VARCHAR(4))+\' \'+ @fldName+\' from \'+@tblName 
120                        +\' where \'+@ID+\' >(select max(\'+ @ID +\') from (\'+ @SqlSelect+\' top \'+ CAST(@pageSize*(@page-1) as Varchar(20)) +\' \'+ @ID +\' from \'+@tblName 
121                        +\' order by \'+ @fldSort +\' \'+ @strFSortType+\') AS TBMinID)\' 
122                        +\' order by \'+ @fldSort +\' \'+ @strFSortType  
123                    end 
124                end     
125            end 
126        else 
127            begin 
128            set @page = @pageIndex-@page+1 --后半部分数据处理 
129                if @page <= 1 --最后一页数据显示                 
130                    set @strTmp=@SqlSelect+\' * from (\'+@SqlSelect+\' top \'+ CAST(@lastcount as VARCHAR(4))+\' \'+ @fldName+\' from \'+@tblName 
131                        +\' order by \'+ @fldSort +\' \'+ @strSortType+\') AS TempTB\'+\' order by \'+ @fldSort +\' \'+ @strFSortType  
132                else 
133                    if @Sort=1 
134                    begin 
135                    set @strTmp=@SqlSelect+\' * from (\'+@SqlSelect+\' top \'+ CAST(@pageSize as VARCHAR(4))+\' \'+ @fldName+\' from \'+@tblName 
136                        +\' where \'+@ID+\' >(select max(\'+ @ID +\') from(\'+ @SqlSelect+\' top \'+ CAST(@pageSize*(@page-2)+@lastcount as Varchar(20)) +\' \'+ @ID +\' from \'+@tblName 
137                        +\' order by \'+ @fldSort +\' \'+ @strSortType+\') AS TBMaxID)\' 
138                        +\' order by \'+ @fldSort +\' \'+ @strSortType+\') AS TempTB\'+\' order by \'+ @fldSort +\' \'+ @strFSortType 
139                    end 
140                    else 
141                    begin 
142                    set @strTmp=@SqlSelect+\' * from (\'+@SqlSelect+\' top \'+ CAST(@pageSize as VARCHAR(4))+\' \'+ @fldName+\' from \'+@tblName 
143                        +\' where \'+@ID+\' <(select min(\'+ @ID +\') from(\'+ @SqlSelect+\' top \'+ CAST(@pageSize*(@page-2)+@lastcount as Varchar(20)) +\' \'+ @ID +\' from \'+@tblName 
144                        +\' order by \'+ @fldSort +\' \'+ @strSortType+\') AS TBMaxID)\' 
145                        +\' order by \'+ @fldSort +\' \'+ @strSortType+\') AS TempTB\'+\' order by \'+ @fldSort +\' \'+ @strFSortType  
146                    end 
147            end 
148    end 
149
150    else --有查询条件 
151    begin 
152        if @pageIndex<2 or @page<=@pageIndex / 2 + @pageIndex % 2   --前半部分数据处理 
153        begin 
154                if @page=1 
155                    set @strTmp=@SqlSelect+\' top \'+ CAST(@pageSize as VARCHAR(4))+\' \'+ @fldName+\' from \'+@tblName                         
156                        +\' where 1=1 \' + @strCondition + \' order by \'+ @fldSort +\' \'+ @strFSortType 
157                else if(@Sort=1) 
158                begin                     
159                    set @strTmp=@SqlSelect+\' top \'+ CAST(@pageSize as VARCHAR(4))+\' \'+ @fldName+\' from \'+@tblName 
160                        +\' where \'+@ID+\' <(select min(\'+ @ID +\') from (\'+ @SqlSelect+\' top \'+ CAST(@pageSize*(@page-1) as Varchar(20)) +\' \'+ @ID +\' from \'+@tblName 
161                        +\' where (1=1) \' + @strCondition +\' order by \'+ @fldSort +\' \'+ @strFSortType+\') AS TBMinID)\' 
162                        +\' \'+ @strCondition +\' order by \'+ @fldSort +\' \'+ @strFSortType 
163                end 
164                else 
165                begin 
166                    set @strTmp=@SqlSelect+\' top \'+ CAST(@pageSize as VARCHAR(4))+\' \'+ @fldName+\' from \'+@tblName 
167                        +\' where \'+@ID+\' >(select max(\'+ @ID +\') from (\'+ @SqlSelect+\' top \'+ CAST(@pageSize*(@page-1) as Varchar(20)) +\' \'+ @ID +\' from \'+@tblName 
168                        +\' where (1=1) \' + @strCondition +\' order by \'+ @fldSort +\' \'+ @strFSortType+\') AS TBMinID)\' 
169                        +\' \'+ @strCondition +\' order by \'+ @fldSort +\' \'+ @strFSortType  
170                end            
171        end 
172        else 
173        begin  
174            set @page = @pageIndex-@page+1 --后半部分数据处理 
175            if @page <= 1 --最后一页数据显示 
176                    set @strTmp=@SqlSelect+\' * from (\'+@SqlSelect+\' top \'+ CAST(@lastcount as VARCHAR(4))+\' \'+ @fldName+\' from \'+@tblName 
177                        +\' where (1=1) \'+ @strCondition +\' order by \'+ @fldSort +\' \'+ @strSortType+\') AS TempTB\'+\' order by \'+ @fldSort +\' \'+ @strFSortType                      
178            else if(@Sort=1) 
179                    set @strTmp=@SqlSelect+\' * from (\'+@SqlSelect+\' top \'+ CAST(@pageSize as VARCHAR(4))+\' \'+ @fldName+\' from \'+@tblName 
180                        +\' where \'+@ID+\' >(select max(\'+ @ID +\') from(\'+ @SqlSelect+\' top \'+ CAST(@pageSize*(@page-2)+@lastcount as Varchar(20)) +\' \'+ @ID +\' from \'+@tblName 
181                        +\' where (1=1) \'+ @strCondition +\' order by \'+ @fldSort +\' \'+ @strSortType+\') AS TBMaxID)\' 
182                        +\' \'+ @strCondition+\' order by \'+ @fldSort +\' \'+ @strSortType+\') AS TempTB\'+\' order by \'+ @fldSort +\' \'+ @strFSortType     
183            else 
184                    set @strTmp=@SqlSelect+\' * from (\'+@SqlSelect+\' top \'+ CAST(@pageSize as VARCHAR(4))+\' \'+ @fldName+\' from \'+@tblName 
185                        +\' where \'+@ID+\' <(select min(\'+ @ID +\') from(\'+ @SqlSelect+\' top \'+ CAST(@pageSize*(@page-2)+@lastcount as Varchar(20)) +\' \'+ @ID +\' from \'+@tblName 
186                        +\' where (1=1) \'+ @strCondition +\' order by \'+ @fldSort +\' \'+ @strSortType+\') AS TBMaxID)\' 
187                        +\' \'+ @strCondition+\' order by \'+ @fldSort +\' \'+ @strSortType+\') AS TempTB\'+\' order by \'+ @fldSort +\' \'+ @strFSortType             
188        end     
189    end 
190
191------返回查询结果----- 
192exec sp_executesql @strTmp 
193select datediff(ms,@timediff,getdate()) as 耗时 
194--print @strTmp 
195SET NOCOUNT OFF 
196GO
197

执行示例:exec proc_paged_2part_selectMax \'tb_testTable\',\'ID,userName,userPWD,userEmail\',10,100000,\'ID\',0,null,\'ID\',0

这种测试只在单机进行,并且没有在实际开发WEB项目中分页测试,测试项也比较单一,所以不够全面系统,但从其效率相比上,我们可以在数据库分页算法上进行有效的控制。

///////////////////////////////////////////////////////////////////////////////////////////////////////

一个使用游标存储过程分页示例:

1 CREATE PROCEDURE [dbo].[im531_Page]
2 @TabeName AS NVARCHAR(50),
3 @Fields AS NVARCHAR(1024),
4 @SearchWhere AS NVARCHAR(1024),
5 @OrderFields AS NVARCHAR(1024),
6 @pageNumber AS INT,
7 @page AS INT
8  AS
9  BEGIN
10 SET NOCOUNT ON;
11 DECLARE @sqlType AS TINYINT
12 SET @sqlType = 0 -- 0 BETWEEN 1 TOP
13   DECLARE @sql AS NVARCHAR(MAX)
14 IF @SearchWhere <> \'\' SET @SearchWhere = \' WHERE \' + @SearchWhere
15 IF @page < 2 SET @page = 1
16 IF @page = 1
17 BEGIN
18 SET @sql = \'SELECT TOP \' + CONVERT(NVARCHAR(20),@pageNumber) + \' \' + @Fields
19 + \'FROM [\' + @TabeName + \'][a] WITH(NOLOCK) \' + @SearchWhere + \' ORDER BY \' + @OrderFields
20 END
21 ELSE
22 BEGIN
23 --临时表
24   SET @sql = \';WITH [Page_____Table] AS(\'
25 + \'SELECT ROW_NUMBER() OVER(ORDER BY \' + @OrderFields + \') AS [RowNow],\' + @Fields
26 + \'FROM [\'+ @TabeName +\' ][a] WITH(NOLOCK) \' + @SearchWhere
27 + \')\'
28 --查找当前页面记录
29   IF @sqlType = 0
30 BEGIN
31 -- A USE BETWEEN
32   SET @sql = @sql + \'SELECT *\'
33 + \'FROM [Page_____Table] WITH(NOLOCK)\'
34 + \'WHERE [RowNow] BETWEEN \' + CONVERT(NVARCHAR(20),(@page - 1) * @pageNumber + 1) + \' AND \' + CONVERT(NVARCHAR(20),@page * @pageNumber)
35 + \'ORDER BY [RowNow]\'
36 END
37 ELSE
38 BEGIN
39 -- B USE TOP
40   SET @sql = @sql + \'SELECT TOP \' + CONVERT(NVARCHAR(20),@pageNumber) + \' *\'
41 + \'FROM [Page_____Table] WITH(NOLOCK)\'
42 + \'WHERE [RowNow] > \' + CONVERT(NVARCHAR(20),(@page - 1) * @pageNumber)
43 + \'ORDER BY [RowNow]\'
44 END
45 END
46 EXEC(@sql)
47  END

分类:

技术点:

相关文章: