entity framework – SQL Server – Automatically full backup for new databases which are auto-created with EntityFramework-Migrations

I have an ASP.NET MVC Application with a Multi-Tenant architecture (using SQL-Server). I’m using EntityFramework DB-Migrations which automatically generates a database per customer.

In SQL-Server I have set up 3 maintenance plans: full, diff and transaction backups. The full-backup happens only once a day.

Now if a new customer-database is auto-generated, the next transaction/differential-backups will fail because there isn’t any full-backup available.

I have found following thread with a similar problem: full-backup-on-database-creation

But in this case a full-backup is created for all databases – which could lead to a longer run. I just want to do a full-backup for the new database (which is empty and should be finished within seconds).

I have tried this by extracting the code from the maintenance plan:

ON ALL SERVER 
FOR CREATE_DATABASE
AS 

SET NOCOUNT ON;
    DECLARE @EventData XML = EVENTDATA();
    DECLARE @db sysname = @EventData.value(N'(/EVENT_INSTANCE/DatabaseName)(1)', N'sysname');
    DECLARE @SubDir nvarchar(1024) =  N'PATH TO BACKUP-LOCATION' + @db;
    DECLARE @BackupName nvarchar(1024) = @db + N'_backup_initial';
    DECLARE @BakFile nvarchar(1024) = @SubDir + N'' + @BackupName + N'.bak';
    DECLARE @ErrMessage nvarchar(1024) = N'Verify failed. Backup information for database ' + @db + ' not found';
    declare @backupSetId as int

    EXECUTE master.dbo.xp_create_subdir @SubDir
    
    exec('BACKUP DATABASE ' + @db + ' TO  DISK = ''' + @BakFile + ''' WITH NOFORMAT, NOINIT,  NAME = ''' + @BackupName + ''', SKIP, REWIND, NOUNLOAD, COMPRESSION, ENCRYPTION(ALGORITHM = AES_256, SERVER CERTIFICATE = (BackupCert)),  STATS = 10, CHECKSUM, CONTINUE_AFTER_ERROR')
        
    select @backupSetId = position from msdb..backupset where database_name=@db and backup_set_id=(select max(backup_set_id) from msdb..backupset where database_name=@db )
    if @backupSetId is null begin raiserror(@ErrMessage, 16, 1) end
    --RESTORE VERIFYONLY FROM  DISK = @BakFile WITH  FILE = @backupSetId,  NOUNLOAD,  NOREWIND
    
GO

Executing the backup-script manually is working, but within the trigger it fails with an error message:

cannot perform a backup or restore operation within a transaction

Does anyone know how to get this working?