Re: What is Weak Entity and Total participation

Abhishek wrote:
> Hi,
> Can you please elaborate on the conceptof total participation of
> entities in ER Modelling?

The total participation of an entity (type) in a certain relationship means that every entity that belongs to the entity type participates in at least one instance of the relationship. For some more explanation see:

http://www.cse.ohio-state.edu/~gurari/course/cse670/cse670Ch2.html

> How is it related to a weak entity? Does a weak entity have to
> participate in a total participation?

Yes. Weak entities cannot be identified by their own attributes but also require the attributes of another entity. (Note: the definition of 'weak entity' may actually differ a bit, depending upon the text-book you are using.) With this other entity they therefore must have some kind of relationship in which their participation is total.

This is not a full explanation but just a hint to push you in the right direction. If you ask inelligent questions more explanation will become available.

• Jan Hidders