批量分离库代码实践

Posted 2020-11-17 jil-wen

 

背景

在实际的工作中，我们可能会针对生产环境的数据库进行维护，需把一些未用或废弃的库分离。针对这个简单需求，基本思路就是使用sp_detach_db分离当前未使用的数据库，我们整理一下批量分离的代码，供后续可以重用。如需批量附加可以参考我们的《批量附加数据库》。

测试环境

Microsoft SQL Server 2012 (SP3-CU2) (KB3137746) - 11.0.6523.0 (X64) 

 Mar 2 2016 21:29:16 

 Copyright (c) Microsoft Corporation

 Web Edition (64-bit) on Windows NT 6.3 <X64> (Build 9600: ) (Hypervisor)

测代代码

 1 --分离代码
 2 USE master;
 3 DECLARE @temp NVARCHAR(4000);
 4 SET @temp = ‘‘;
 5 DECLARE cursorname CURSOR FORWARD_ONLY
 6 FOR
 7 SELECT name
 8 FROM sys.databases
 9 WHERE database_id > 4
10       AND name LIKE ‘test_%‘
11       AND state_desc = ‘online‘
12       AND is_read_only = 0
13       AND is_published = 0
14       AND name IN ( ‘test_1012986‘, ‘test_1012846‘, ‘test_1012852‘,
15                       ‘test_1012766‘, ‘test_1012744‘, ‘test_1012743‘,
16                       ‘test_1012601‘, ‘test_1012448‘, ‘test_1012302‘,
17                       ‘test_1012187‘, ‘test_1012051‘, ‘test_1011929‘,
18                       ‘test_1011919‘, ‘test_1011880‘, ‘test_1011735‘,
19                       ‘test_1011734‘, ‘test_1011587‘, ‘test_1011440‘,
20                       ‘test_1011439‘, ‘test_1011127‘, ‘test_1011061‘,
21                       ‘test_1011021‘, ‘test_1011006‘, ‘test_1010999‘,
22                       ‘test_1010916‘, ‘test_1010833‘, ‘test_1010663‘          
23                   );
24 
25 OPEN cursorname;
26 DECLARE @curname NVARCHAR(50);
27 FETCH NEXT FROM cursorname
28 INTO @curname;
29 WHILE (
30           @@fetch_status = 0
31       )
32 BEGIN
33     ---提前判断一下该库是否有链接，如有则kill对应的库的链接
34     IF
35     (
36         SELECT COUNT(1)
37         FROM sys.sysprocesses
38         WHERE DB_NAME(dbid) = @curname
39     ) >= 1
40     BEGIN
41         DECLARE @spid VARCHAR(200);
42         DECLARE cur_spid CURSOR FORWARD_ONLY
43         FOR
44         SELECT spid
45         FROM sys.sysprocesses
46         WHERE DB_NAME(dbid) = @curname;
47         OPEN cur_spid;
48         FETCH NEXT FROM cur_spid
49         INTO @spid;
50         WHILE (
51                   @@fetch_status = 0
52               )
53         BEGIN
54             EXEC (‘ kill   ‘ + @spid);
55             -- PRINT (‘ kill   ‘ + @spid);
56             FETCH NEXT FROM cur_spid
57             INTO @spid;
58         END;
59         CLOSE cur_spid;
60         DEALLOCATE cur_spid;
61         SET @temp
62             = N‘ EXEC sp_detach_db ‘ + ‘‘‘‘ + @curname + ‘‘‘‘ + ‘, true‘;
63         EXEC (@temp);
64     -- PRINT @temp;
65     END;
66     ELSE
67     BEGIN
68         SET @temp
69             = N‘ EXEC sp_detach_db ‘ + ‘‘‘‘ + @curname + ‘‘‘‘ + ‘, true‘;
70         EXEC (@temp);    
71        -- PRINT @temp;
72     END;
73     FETCH NEXT FROM cursorname
74     INTO @curname;
75 END;
76 CLOSE cursorname;
77 DEALLOCATE cursorname;

1 --验证代码
2 SELECT name FROM sys.databases

 

 

总结

• 注意执行上述脚本的权限的问题；
• 注意在生产环境要先测试验证；
• 上述脚本的逻辑主要是使用的游标实现，未使用sp_MSforeachdb，实际该存储过程也是用游标实现且有些限制，除使用游标外还可以使用while加row_number()来替换；

参考

sp_detach_db