Register user in my own table and access information from it.

Hello everyone, I'm developing chat app in Android, I achieved basic functionality using openfire and smack api, now I need to make it in web client too. So to synchronize between web client and app user I need to use register user from app/webclient in my own table and not in ofusers table . I followed custom database setup with MySQL but its not working and I even want to access user information from my own custom table through webservice so I think I'll have to use restapi to make http call , am I right ? I'm so confused please help me.