CODEWITHSUNDEEP
entity-relationshipspecialization
FurioShow
FurioShow

Reputation: 21

About subtypes in EER Model

Can a subtype doesn't have any local attributes?

For example, if I have to create subtypes about the phase of a tournament, as GroupStage, Quarter Finals, Semi Finals and Final I'd better create an attribute or a specialization?

Upvotes: 0

Views: 720

Answers (1)

reaanb
reaanb

Reputation: 10065

Subtypes are used for specialized attributes and/or relationships, so, yes, you can have subtypes that don't have additional attributes. However, if you don't have either specialized attributes or relationships, it's simpler to add an attribute on your main entity set than to create subtypes. Changing an entity from one subtype to another also requires more effort, so try to use subtypes for roles that don't normally change, rather than for states that vary over time.

Upvotes: 1

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