Database - Data Modeling with ER Model - Discussion

Discussion Forum : Data Modeling with ER Model - General Questions (Q.No. 4)
4.
Which type of entity represents an actual occurrence of an associated generalized entity?
Supertype entity
Subtype entity
Archetype entity
Instance entity
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
9 comments Page 1 of 1.

Yogeetha said:   4 years ago
Now, It's clear. Thanks @Jiten @Debanjan Dey.

Selvam said:   6 years ago
Can someone explain it please?

Debanjan dey said:   8 years ago
Suppose Brad Pitt is an instance of a person. He may or may not be an employee or a student but a person indeed. So we choose the instance.

Pankaj Das said:   8 years ago
@Jiten.

Subtype will also correct. If PERSON is a generalized entity, then EMPLOYEE, STUDENT these are subtype entity.

How did you explain here? It seems the subtype and instance entity both is synonymous.

But, as we have both the option in the question, it caused the confusion.

Sonal said:   8 years ago
Can someone elaborate the types of entities that are given in the question?

Jiten said:   1 decade ago
It might help to think of an entity as a thing.

So you are asking about a type of thing, and an actual instance of that thing.

For example, one type of thing is a Person. Brad Pitt is an instance of a Person. A Fruit is a type of thing, and an Apple is an instance of a Fruit.

Make sense?

In a database world you might name a table after the type of an entity, like a Car. However, each record in the table is an instance of a Car, like Ford Mustang.

David said:   1 decade ago
What is an instance entity?

Prince Singh said:   1 decade ago
Can someone explain this answer?

Harshit said:   1 decade ago
Can somebody elaborate this answer ?

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