Creating a one to many polymorphic relationship with doctrine

Question

Let me start by outlining the scenario. I have a Note object that can be assigned to many different objects

• A Book can have one or moreNot

Answer 1

This question introduces unneccessary complexity into the application. Just because the notes have the same structure does not mean that they are the same entity. When modelling the database in 3NF, they are not the same entity because a note can not be moved from a Book to an Address. In your description there is a definitive parent-child relation between book and book_note, etc so model it as such.

More tables is not a problem for the database but unneccessary code complexity is, as this question demonstrates. It is just being clever for clevers sake. This is the trouble with ORMs, people stop doing full normalization and don't model the database correctly.