How to Reduce Log File Size in SQL Server

First
Use [database name];
Exec sp_helpfile;

You can use sp_helpfile to query the logic name of the log file, and then you can use DBCC to reduce the LOG file
Backup log [database name] WITH TRUNCATE_ONLY
Dbcc shrinkfile ([logical name of log file], 1)

This method is no longer applicable in ms SQL Server 2008 and ms SQL Server 2008 R2, and the prompt is: TRUNCATE_ONLY is not a valid BACKUP option.

This operation method should be adopted:

Copy codeThe Code is as follows: -- first, change the database recovery mode to Simple.
Alter database [DATABASE name] set recovery simple;
GO
-- Reduce the log file to 1 M. The logical name can be obtained through sp_helpfile.
Dbcc shrinkfile ([log File logical name], 1 );
GO
-- Reset the recovery mode of the database
Alter database [DATABASE name] set recovery full;
GO