Summary

Visual LANSA Logical Modeler

Summary

Important Observations

  • A Variant entity can only inherit its identifying element(s) from another entity by means of a Variation relationship.
  • You cannot assign an identifying element when working with elements of a Variant entity.

Tips and Techniques

  • Ensure you create an element in the source entity of the Variation relationship that will hold the entity's type of variation in the resultant database.
  • Variant entities and variation relationships are used when you want to avoid sparsely populated databases. For example, you could include all elements from the Supplied Product and Manufactured Product entities into the Product Entity. If you combine these entities into one file, you will notice that all fields relating to a Manufactured Product will be blank whenever a Product is a Supplied Product, and vice versa. Hence, you will have a database with many unused fields. Using variations allows information to be grouped or categorized. The Supplied Product file will only contains records for Supplied Products and not for every record in the Product File.

What I Should Know

  • How to create a Variant entity.
  • How to create a Variation relationship between a Data entity and a Variant entity.