If you have data modeling experience, the concept of relationships will be very familiar to you. If you are unfamiliar with data modeling, you should attend the LANSA Modeling and Design Workshop as this guide is not designed to teach you the principles of data modeling.
Once you have created your entities, you can define relationships between them. The Logical Modeler supports extended Chen E-R relationships. These include the basic Parent/Child and Join relationships along with extensions to Chen E-R relationships such as Optional Join, Variation and Include.
Relationships are very important. At a data level, a Parent/Child relationship will cause the keys of a parent entity to cascade to the child entity.
Relationships influence the file keys, logical files, referential integrity validation rules and access routes which are generated when the model is built in the LANSA Repository.
This information is described in: