Use of Entity or Relationship Sets

Posted By on October 3, 2014


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Mapping Cardinalities
Use of Extended E-R Features

Use of Entity or Relationship Sets

It is not always clear whether an object is best represented by an entity set or a relationship set.

  • Figure  shows how we might model an account as a relationship between a customer and a branch.  
    Figure : E-R diagram with account as a relationship set
  • This new representation cannot model adequately the situation where customers may have joint accounts. (Why not?)
  • If every account is held by only one customer, this method works.

 

Mapping Cardinalities
Use of Extended E-R Features

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Posted by Akash Kurup

Founder and C.E.O, World4Engineers Educationist and Entrepreneur by passion. Orator and blogger by hobby

Website: http://world4engineers.com