其实基本上有三种方法:
1、使用SQL Server 2005中新增的ROW_NUMBER
几种写法分别如下:
1SELECT TOP 20 * FROM (SELECT
2 ROW_NUMBER() OVER (ORDER BY Namec) AS RowNumber,
3 *
4FROM
5 dbo.mem_member) _myResults
6WHERE
7 RowNumber > 10000
8
1SELECT * FROM (SELECT
2 ROW_NUMBER() OVER (ORDER BY Namec) AS RowNumber,
3 *
4FROM
5 dbo.mem_member) _myResults
6WHERE
7 RowNumber between 10000 and 10020
1WITH OrderedResults AS
2
3(SELECT *, ROW_NUMBER() OVER (order by Namec) as RowNumber FROM dbo.mem_member)
4
5SELECT *
6
7FROM OrderedResults
8
9WHERE RowNumber between 10000 and 10020
不管哪种写法,性能都不理想。在8,9万条数据的情况下要运行6秒左右。
2、使用临时表再加存储过程
1BEGIN
2 DECLARE @PageLowerBound int
3 DECLARE @PageUpperBound int
4
5 -- Set the page bounds
6 SET @PageLowerBound = 10000
7 SET @PageUpperBound = 10020
8
9 -- Create a temp table to store the select results
10 Create Table #PageIndex
11 (
12 [IndexId] int IDENTITY (1, 1) NOT NULL,
13 [Id] varchar(18)
14 )
15
16 -- Insert into the temp table
17 declare @SQL as nvarchar(4000)
18 SET @SQL = 'INSERT INTO #PageIndex (Id)'
19 SET @SQL = @SQL + ' SELECT'
20 SET @SQL = @SQL + ' TOP ' + convert(nvarchar, @PageUpperBound)
21 SET @SQL = @SQL + ' m_id'
22 SET @SQL = @SQL + ' FROM dbo.mem_member'
23 SET @SQL = @SQL + ' ORDER BY NameC'
24
25 -- Populate the temp table
26 exec sp_executesql @SQL
27
28 -- Return paged results
29 SELECT O.*
30 FROM
31 dbo.mem_member O,
32 #PageIndex PageIndex
33 WHERE
34 PageIndex.IndexID > @PageLowerBound
35 AND O.[m_Id] = PageIndex.[Id]
36 ORDER BY
37 PageIndex.IndexID
38
39drop table #PageIndex
40 END
而使用这种方法,在同样的情况下用时只需1秒。
看样子,row_number是个鸡肋。
3、如果觉得临时表不好,还可以使用SET ROWCOUNT
1begin
2DECLARE @first_id varchar(18), @startRow int
3
4SET ROWCOUNT 10000
5SELECT @first_id = m_id FROM mem_member ORDER BY m_id
6
7SET ROWCOUNT 20
8
9SELECT m.*
10FROM mem_member m
11WHERE m_id >= @first_id
12ORDER BY m.m_id
13
14SET ROWCOUNT 0
15end
不过,这种方法有缺点。按ID排序就快,按其他字段排序就慢。
大家有什么意见,欢迎拍砖。
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