DECLARE @name VARCHAR(50); -- Database name
DECLARE @path VARCHAR(256); -- Path for backup files
DECLARE @fileName VARCHAR(256); -- Filename for backup
DECLARE @fileDate VARCHAR(20); -- Used for file name
DECLARE @DeleteDate DATETIME = DATEADD(wk,-2,GETDATE()); -- Cutoff date minus 2 weeks on this example

-- Path to backups.
SET @path = 'D:\Backup\';

-- Get date to include in file name.
SELECT @fileDate = CONVERT(VARCHAR(20),GETDATE(),112);

-- Dynamically get each database on the server.
DECLARE db_cursor CURSOR FOR
SELECT name
FROM master.sys.databases
WHERE name NOT IN ('master','model','msdb','tempdb');

OPEN db_cursor;
FETCH NEXT FROM db_cursor INTO @name;

-- Loop through the list to backup each database.
WHILE @@FETCH_STATUS = 0
BEGIN 
      -- Build the path and file name.
      SET @fileName = @path + @name + '_' + @fileDate + '.BAK';
      -- Backup the database.
      BACKUP DATABASE @name TO DISK = @fileName WITH INIT;
      -- Loop to the next database.
      FETCH NEXT FROM db_cursor INTO @name;
END 

-- Purge old backup files from disk.
EXEC master.sys.xp_delete_file 0,@path,'BAK',@DeleteDate,0;

-- Clean up.
CLOSE db_cursor;
DEALLOCATE db_cursor;
GO