title: One to many relationship
body: <p>To start off, we have the following scenario (not exactly like this but for confidential reason I will not take the risk to explicitly describe the project) where let's say A person can Have Many home addresses and obviously an address belong to at most one person. This is pretty much a one to many relationship where there are 2 tables (Person and Addresses) with the second one holding a FK referencing the owner. But sadly i was told that my system should also allow users to enter  Addresses first, so a FK that does not exist in the Person table yet. I came to the conclusion that i just have to drop that constraint. Do you thing it's a common thing to do? Furthermore I thought to maintain consistency even without FK (declared explicitly), if someone update the Person ID, since i dont want the user to do it in both table, is it possible to create a Trigger (I'm using Mysql server) that will update the second table automatically (if that person has an address)? If yes, any hint to how to  write that (I'm not familiar with triggers)</p>