Suppose you try to take a log backup of a SQL database, and it gives the error message - Msg 4214, Level 16, State 1, Line 1 BACKUP LOG cannot be performed because there is no current database backup.
You require a full backup for a new SQL Database in full recovery mode before taking any transaction log backup. You get the error message if you try to take a log backup for a new database without a full backup.
As shown below, after taking a full backup, log backup executes successfully.
Backup Database TestDB to disk='TestDB.bak' go Backup Log TestDB to disk='TestDB.trn'