update iphone application behaviour

I developed one database related applic开发者_如何学Cation for iPhone device(SQlite database). Now i want to update that application with more features(I want to push an update for the same application).

Here i am more concerned about the user data while pushing the update so my question is if i will push an update then does the update will clear all the data that is stored in .sqlite file?

if this is case then how to push application update without modifying the previous data in the database file?

Please suggest.

AFAIK the documents directory is left in-tact on an update. If you stored the database in the documents directory then you should be okay. If it's in the app's bundle, I don't think there is much you can do save it.