Define cardinality and participation constraints, Database Management System

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Define cardinality and participation constraints on a relationship type, completeness constraint on generalization.       

Ans: Cardinality defines the number of entities to which other entity can be related via a relationship set. It may be 1:1, 1: N or M: N.

 In a relationship set Participation of an entity set can be total or partial. It is total if each entity participates in the relationship. If only a few entities participate in a relationship after that it is partial.

Completeness constraint may be partial or total. In the case of total every higher level entity must belong to a lower level entity and in the case of partial few higher level entities might not belong to lower level entities.


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