title: How to add connection of Android application with existing phonebook contact programmatically like facebook, whatsapp, freecharge etc?
body: <p>I have tried using [this][1]</p>
  
  <p>[1]: <a href="https://stackoverflow.com/questions/29846912/adding-new-connection-to-existing-android-contact/29848214#29848214">Adding new connection to existing android contact</a> to update existing contact with my app's connection. but it is adding new contact with same details and no account connection is getting added to it :(</p>
  
  <p>Please tell me how to achieve this and which columns (eg name, phone number, email, etc) are mandatory to update the existing contact so that it will get merged into existing one without getting new one created.
  Please help me!</p>
  
  <p>Also another question- can we add custom fields in the existing device contacts? If yes, how?</p>
  
  <p>Thanks in advance :)</p>