How to recover from mdf file (SQL Server 2000)

Question

Hi,
My database corrupted because when I was running an update query, there is a power failure. After the computer booted, I cannot open the database anymore, it just not responding. Then I stop the sql server service, and tried to rename the .mdf and .ldf. After that it worked normally, but I need the data from the corrupted mdf file, I tried to attach the database but it just hanged. I even tried to attach without the .ldf file but it didn't work either, so I concluded that the problem is with the mdf file.
Is there any way to recover my data ??
Thanks in advance
Regards,
Edwin

Answer 1

Try this undocumented stuff provided by Kevin [MS].
==========
1. Back up the .mdf/.ndf files at first!!!
2. Change the database context to Master and allow updates to system tables:
Use Master
Go
sp_configure 'allow updates', 1
reconfigure with override
Go
3. Set the database in Emergency (bypass recovery) mode:
select * from sysdatabases where name = '<db_name>'
-- note the value of the status column for later use in # 6
begin tran
update sysdatabases set status = 32768 where name = '<db_name>'
-- Verify one row is updated before committing
commit tran
4. Stop and restart SQL server.
5. Call DBCC REBUILD_LOG command to rebuild a "blank" log file based on the
suspected db.
The syntax for DBCC REBUILD_LOG is as follows:
DBCC rebuild_log('<db_name>','<log_filename>')
where <db_name> is the name of the database and <log_filename> is
the physical path to the new log file, not a logical file name. If you
do not
specify the full path, the new log is created in the Windows NT system
root
directory (by default, this is the Winnt\System32 directory).
6. Set the database in single-user mode and run DBCC CHECKDB to validate
physical consistency:
sp_dboption '<db_name>', 'single user', 'true'
DBCC checkdb('<db_name>')
Go
begin tran
update sysdatabases set status = <prior value> where name = '<db_name>'
-- verify one row is updated before committing
commit tran
Go
7. Turn off the updates to system tables by using:
sp_configure 'allow updates', 0
reconfigure with override
Go
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