data modeling - How to draw an ER diagram where there are 2 entities with exactly same attributes - Stack Overflow

Each appliance is classified as either: Kitchen appliances, Entertainment appliances, and it’s important to keep track of their type.

Kitchen appliances and Entertainment appliances have details about weight and dimensions. But, for entertainment appliances also store details about power consumption and display size.

Some appliances, called Smart appliances, have both kitchen and entertainment features.

Draw an ER diagram for this. What I am confused about is how to model Entertainment appliances and Smart appliances because both of them would be having the same attributes.

Each appliance is classified as either: Kitchen appliances, Entertainment appliances, and it’s important to keep track of their type.

Kitchen appliances and Entertainment appliances have details about weight and dimensions. But, for entertainment appliances also store details about power consumption and display size.

Some appliances, called Smart appliances, have both kitchen and entertainment features.

Draw an ER diagram for this. What I am confused about is how to model Entertainment appliances and Smart appliances because both of them would be having the same attributes.

• data-modeling
• entity-relationship
• erd

Share Improve this question Follow edited Feb 2 at 12:48 OutOfBounds asked Feb 2 at 11:05 OutOfBoundsOutOfBounds 9711 silver badge88 bronze badges 4

• Based on your description, the two entities would have similar, but not the same attributes. In terms of drawing the diagram: just draw two entities as usual. The real question will come when modelling these relationships in your database. – Shadow Commented Feb 2 at 11:19
• There are three entities here though - Kitchen appliances, Entertainment appliances and smart appliances. Can you pls elaborate why you mentioned 2 entities? – OutOfBounds Commented Feb 2 at 12:03
• Each appliance falls into one of the 2 categories: Kitchen appliances, Entertainment appliances - explain where the third comes from. Perhaps you should rewrite your question to be clearer. – Shadow Commented Feb 2 at 12:20
• I have edited, can you pls have a look now. it does not start 2 explicitly. but when u read the question, then u will notice there is a third category that is a hybrid of both. – OutOfBounds Commented Feb 2 at 12:49

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Honestly, i'd just make one entity and then add an extra attribute called "type"