sriki

• Feb 14th, 2007

 

Agragation is Weak relation between the two entities, means when then one entity is delteted, then other object will not get affected.

rashmitambe

 Profile Answers by rashmitambe 

• Apr 20th, 2007

 

Aggregation is a special type of ‘has-a’ relationship between classes where one of the two participating classes is part of other one. I.e. it’s a ‘whole-part’ relationship. The class acting as ‘whole’ always has multiplicity of one.

 In UML representation, aggregations are represented by an association that shows a rhomb on the side of the whole.

For example, A car has Wheels.

Composition is a special type aggregation where the 'has-a' relationship is more strong. I.e. the part entity cannot exist without the whole entity. For example, an university has departments, which cannot exist on their own with the containing 'university' entity.