I'm going to move your thread to the
Database Concepts & Design forum. It will probably get many more folks that can help you there, since the
New Members & Introductions forum is really intended and used more for "Hello, World" kinds of messages.
First and foremost, very few if any of the regulars at DBForums will actually
DO your homework for you. Most of us are glad to help, and the more effort you put foreward, the more likely we are to help. If someone appears willing to actually DO your homework for you, be very, VERY wary. I won't explain why you need to be wary, but trust me on this one... You do!
Now, on to your question! You have to think carefully about how your cell phone's contact database works. There are significant differences in how the cell phone's "phonebook" works. If you can tell us what model phone you've got, it will help a great deal in getting you specific answers and guidance.
Newer cell phones tend to look at phonebooks as a collection of name each name having a collection of phone numbers of different types. Most older cell phones tend to look as a phonebook consisting of names associated with single numbers. There are important differences between these two perspectives when it comes to data (ERD) modeling.
Anywho, welcome to DBForums!
-PatP