System development/course/data items, attributes and relations

Relations

Draw together with the student some examples on a whiteboard or piece of paper. Explain what questions you should ask yourself to make the right decision about how a relation should be build in Triggre.

Possible examples are:

• Order – Orderrule
  • Start with a one to many relation.
• Employee – Project
  • Then explain the many to many relation.
• Person – LastName
  • In a lot of applications the relation between Person and LastName will be a 1-1 relation, LastName is an attribute of Person.
  • In SAP the lastname is registered in infotype 0002, see http://nl.sap.wikia.com/wiki/IT0002 for screenshot. At the top of the screen you can register a start an end date. Now the relation is a 1 to many relation.
• Person – Address
  • In a lot of applications the relation between Peson and Address will be a 1-1 relation.
  • In an eHRM portal however you want to give your employees the opportunity to register their future move to a new house in advance. So you need a many to many relation.

* Employee – Person

• • Also add the concepts: Applicant, Contact.
• Leasecare – driver