Participation constraints, Database Management System

The participation Constraints shows whether the existence of an entity depends on its being associated to another entity by the relationship type. There are two kinds of participation constraints:

Total: When the entire entities from an entity set participate in a relationship type, is known as total participation, for instance, the participation of the entity set student in the relationship set have to 'opts' is said to be total as each student enrolled must opt for a course.

Partial: When it is not necessary for all the entities from an entity set to partake in a relationship type, it is known as partial participation. For instance, the participation of the entity set student in 'represents' is partial, as not every student in a class is a class representative.

Posted Date: 3/6/2013 6:12:10 AM | Location : United States

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