It is possible to know the Iphone's Contact DataBase struct? (iphone sdk)

I have to made an app, my app's users have a list of contacts, I w开发者_JAVA百科ould like to use the same DB struct of the iphone,also because I have to have the possibility to merge two or more contacts in my app's contactslist. thank to all and sorry for my bad English!!!

See Address Book Programming Guide for iOS

You not acces to the data base structure but you can access to records and properties with interfaces.

Why you app contact list can't be in the iPhone address book ?