Consider the ER diagram on the attached image (if attached).
which is the first image on http://www.yiiframework.com/doc/guide/1.1/en/database.arr page.
I have a question about Post-Category Many_Many relation.
In order to simulate my case lets assume that not every user
can use each Category. Namely the categories can one user select
are restricted to some subset of all categories. Lets assume in the user
table (or in another table) we put the category ids that user can select.
In this situation , how can I write a many-many relation between Post-Category
which only joins that user’s post categories?