Toad World® Forums

Urgent Help on Defining Relationships


Hi, I have been trying to define relationships in a logical model, where attributes of one antity are transfered to the other entity and vice versa. is this possible and how do I need to define the relationship in the cardinality tab?



In LER model, keys are not transferred from parent to child entity when you create a relationship.

Please have a look at the Help file, e.g. Index tab and type ‘conversion’, see the topic PER-LER details and other topics related to logical modeling.





There is a very good reason for this too by the way - logical models are meant to capture business requirements without concern for the implementation methodology (i.e. relation database). So if the logical model is decided to be implemented as a flat file system, there is no such thing as foreign keys. So the physical model is where one sees these appear. This is not a Toad Data Modeler constraint - but how data modeling has been defined to be done.