Re: Normalizing the ER model

Greg Boland wrote:
>
>I like ORM because of the contraints one can apply to relationships.

Good. I like ORM because it has a good linguistic and philosophical foundation and its semantics are formally described. :-)

>But in my experience, these constraints are usually implemented by stored
>procedures or some other procedural logic. So what does normalization have
>to do with it?

A fact type is a relation so all of normalization theory applies to it directly. For example if you have a fact type with the roles Street, Number, City and Zipcode then it is not in BCNF if Zipcode only determines Street and City. However, AFAIK there is no graphical notation for functional (or other) dependencies in ORM.

• Jan Hidders