sqlite table is empty after relaunching the android app

sqlite table is empty after relaunching the android app

in my app I access my sqlite db in two ways. one from a service which
fetches the data from the server and updates the database. and two there
are other methods that read the data and show it to the user. what happens
is that that when I update the database, when I close the app and open it
again, the data is gone and tables are empty?!?! I open the db when I
launch the app and close (if I do) in onDestroy().