Surprise from Google: in the KitKat your SD-card is useless for now.

In the Android 4.4.x (KitKat an above) there is no way for now to write the application database to the external storage (SD-card). This is surprise from Google. The only one legal way on the stock ROMs — you should move your database folder into the internal storage. However, app can creating a backup copies and restore files into SD card.