First Normal Form

The classic discussion point is "OK, so you have phone1, phone2 and phone3, so what happens if one customer has 4 phones?". If your design is vulnerable to such a point then it is not in 1NF. – Greenstone Walker May 6 at 1:52 http://dba.stackexchange.com/questions/41552/challenge-build-mysql-table-thats-not-in-first-normal-form