> For all the ERD's do we have to make association entities to account for

> the many to many relationships...or can we just leave them.

You can leave the many-to-many relationships as they are. We'll talk about converting from the E-R diagram to a database on Tuesday. At that point you'll have to build a separate table (typically called a "bridge" table) for the many-to-many's, but you don't have worry about them for the homework.


> For the first question, when you said multiple minors are allowed, we can

> make a minor entity to account for this? Maybe i'm not looking outside of

> the box, but right now I'm just making the entities s student, course, and

> instructor and trying to add the rest of the info as attributes, which i

> think won't work.

Actually, it will work fine to just have those three entities. Go back at look at the types of attributes that can be identified, specifically multivalued attributes (hint, hint).


> for the 3rd question. 2nd part.. it asks to ONLY use a binary relationship.

> Does that mean only use two entities? Many entities could be used though..

> Laboratory, Projects, Chemists, Equipment. I'm just not sure how to handle

> this problem. Thanks.

It's not only using two entities. You are to do it using only relationships that involve two entities (binary). You are to either draw a diagram that reflects the requirements but only uses binary relationships or explain what information will be lost without a ternary (three entity) relationship of associative entity (relationship with attributes).

> I was trying to do ER diagramming in MS powerpoint, but it's very time

> consuming, but I wasn't able to find the E-R diagramming tool in

> Visio. Do you have any suggestions?

The diagram type in Visio is under "database" and is a "Chen ERD".