Check for full SQL Server database backups before creating other backups

CREATE PROCEDURE sp_generateDifferentialBackups  
   @strBackupPath NVARCHAR (25) ='D:\backups\' --variable for location of DIFFERENTIAL backups  
AS  
SET NOCOUNT ON   
-- Get the name of all user databases    
DECLARE @strTimeStamp NVARCHAR(12)   --variable for timestamp value   
DECLARE @strSQL NVARCHAR(100)        -- used for generating dynamic SQL statements   
DECLARE @databaseName NVARCHAR(128)  -- used as variable to store database names   
DECLARE dbCursor CURSOR FOR          -- used for cursor allocation   
   SELECT NAME  
   FROM MASTER.SYS.DATABASES  
   WHERE [database_id] > 0  
   AND NAME NOT IN ('MASTER','MODEL','MSDB','TEMPDB') --does not include the system databases   

OPEN dbCursor   
   
FETCH NEXT FROM dbCursor INTO @databaseName   
   
WHILE (@@FETCH_STATUS = 0)   
BEGIN   
   PRINT 'Checking for the latest FULL database backup for: [' + @databaseName +']'  
       
   DECLARE @strphysical_device_name NVARCHAR(100) -- variable for physical_device_name   
   DECLARE @cursor NVARCHAR(400)   

   -- Reads the MSDB database to check for the latest FULL database backup         
   SELECT @cursor=('DECLARE TabCursor CURSOR FAST_FORWARD GLOBAL FOR ' +   
   'SELECT TOP 1 physical_device_name   
   FROM msdb.dbo.backupset a INNER JOIN msdb.dbo.backupmediafamily b      
   ON a.media_set_id = b.media_set_id      
   WHERE database_name=''' + @databaseName + '''   
   AND type=''D''   
   ORDER BY backup_finish_date desc')   
   EXEC sp_executesql @cursor   
   OPEN TabCursor   
   
   FETCH NEXT FROM TabCursor INTO @strphysical_device_name   
   --Check if the database does not have any FULL backups at all  
   IF @@FETCH_STATUS <> 0  
   BEGIN  
      PRINT '*****WARNING: Database [' + @databaseName + '] does not have any FULL database backups at all. Generate the FULL database backup first. Aborting DIFFERENTIAL backup command.*****'  
   END  
   ELSE     
   --If the database has FULL backups,  
   WHILE @@FETCH_STATUS = 0   
   BEGIN   
      DECLARE @result INT   
      EXEC xp_fileexist @strphysical_device_name, @result output    
      IF (@result = 1)  --@result will return 1 if the specified file exists, if it doesn't, it will return 0   
      BEGIN   
         SET @strTimeStamp=CONVERT(CHAR(8), GETDATE(), 112)   
         SET @strTimeStamp=@strTimeStamp + REPLACE(CONVERT(CHAR(8), GETDATE(), 108),':','')   
         EXEC ('BACKUP DATABASE ' + @databaseName + ' TO DISK=''' + @strBackupPath + @databaseName + '_DIFF_' + @strTimeStamp + '.BAK'' WITH INIT, DIFFERENTIAL, DESCRIPTION=''DIFFERENTIAL Backup for ' + @databasename + ' database''') -- change this value should you decide to change the backup type to something other than differential    
         PRINT '==========================================================================================='   
         PRINT 'DIFFERENTIAL Backup generated for database: [' + @databaseName  + ']'  
         PRINT 'Corresponding FULL database backup: ' + @strphysical_device_name   
         PRINT 'DIFFERENTIAL database backup: ' + @strBackupPath + @databaseName + '_DIFF_' + @strTimeStamp + '.BAK'   
      END   
      ELSE   
         PRINT  '*********WARNING: FULL database backup file is missing. Generate the FULL database backup first. Aborting DIFFERENTIAL backup command.*********'   
          
      FETCH NEXT FROM TabCursor INTO @strphysical_device_name   
   END   
   CLOSE TabCursor   
   DEALLOCATE TabCursor   
        
   PRINT '==========================================================================================='   
   PRINT '                                                                                           '   
   PRINT '                                                                                           '   
   PRINT '                                                                                           '   
    
   FETCH NEXT FROM dbCursor INTO @databaseName   
END   
   
CLOSE dbCursor   
DEALLOCATE dbCursor   

PRINT 'FINISHED'   
GO