We now handle data facets one to represent connections among agencies, hence i phone call dating
Feature Connection
Mount attributes to your agencies they really really define. Including, this new attribute place of work-building-title would be to typically be a characteristic of the organization Agency, rather than the organization Worker. The process of identifying entities and you can attaching functions in order to entities is actually iterative. Identify some data facets because agencies and you will attach identifiers and you may descriptors on it. If you discover certain admission of your own before direction, change specific investigation points away from entity so you’re able to attribute (or away from characteristic so you’re able to entity), mount properties with the the fresh agencies, etc.
Select the fresh new Generalization Hierarchies
If there’s an effective generalization ladder one of organizations, then place the identifier and you will general descriptors on supertype entity and set an equivalent identifier and you will particular descriptors regarding subtype organizations.
What if we dictate, through the research, that the entity Worker is written just like the good generalization off Director, Engineer, Professional, and you will Assistant. Following we set identifier empno and general descriptors empname, target, and you can time-of-birth about supertype entity Staff; identifier empno and you will specific descriptor jobtitle their site on subtype organization Movie director; identifier empno and you can certain descriptor higher-degree and jobtitle on subtype entity Professional; etcetera. (περισσότερα…)