I thought it was alias for simple foreign key relation,but seems not.
Can you take MySQL as an example what is association relation?
I guess it means many2many relation,is that true?
+2
A:
You confuse relation and relationship here. These are different concepts.
An association relationship is a class theory concept. This is a relationship between two or more entities that does not imply any limitations on their life cycles.
Say, friendship is an association relationship: a person can be a friend to one or more persons, but when the friendship ends, no actual persons are erased from existence.
In relational databases, this is usually represented with a many-to-many link table with FOREIGN KEY references to the tables holding primary keys of the entities associated.
Quassnoi
2010-03-04 14:07:01