Sometimes you may face error “The transaction log for database is full due to ‘LOG_BACKUP’” this error due to your database has been setup as full recovery model and transaction log becomes full due to LOG_BACKUP. and due to this, you will not be able to perform any transaction on this database.
To resolve the issue, take transaction log backup and set the database in simple recovery model.
To do so you need to do the following
Change database model to SIMPLE Recovery
ALTER DATABASE Database_name SET RECOVERY SIMPLE GO
Truncate log file
DBCC SHRINKFILE (Database_name, 1); GO
Reset model to FULL Recovery
ALTER DATABASE Database_name SET RECOVERY FULL GO