【IT168 服务器学院】详细步骤：

a. Change the database context to Master and allow updates to system tables:
 
   Use Master
   Go
   sp_configure ''allow updates'', 1
   reconfigure with override
   Go
b. 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
   begin tran
   update sysdatabases set status = 32768 where name = ''<db_name>''
   -- Verify one row is updated before committing
   commit tran
c. Stop and restart SQL server.
d. The syntax for DBCC REBUILD_LOG is as follows:
   DBCC REBUILD_LOG(''<db_name>'',''<log_filename>'')
e. Set the database in single-user mode and run DBCC CHECKDB to validate physical consistency:
  
-- Put database in single user mode and run CHECKDB.
   sp_dboption ''<db_name>'', ''single user'', ''true''
   DBCC CHECKDB(''<db_name>'')
   Go
   -- Address any errors reported by CHECKDB.
   -- Take the database out of single user mode.
   sp_dboption ''<db_name>'', ''single user'', ''false''
f. Turn off the updates to system tables by using:
  
   sp_configure ''allow updates'', 0
   reconfigure with override
   Go