How to rewrite database

I am doing an app which uses sqlite d开发者_运维问答b. When the app start it has to update by rewriting the data from a URL by checking the data in it.

Please suggest me how can I do this, or give me a reference to follow.

Thank you

try this http://www.screaming-penguin.com/node/7742

and

http://www.devx.com/wireless/Article/40842