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Artificial primary keys in many-to-many relationships

Sergio González (IT teacher) 5 ár síðan • updated by Adam Mościcki 5 ár síðan • 1

Checking your article "A Dating App Data Model" I saw that in relations that appear from a many-to-many relationship (for instance between relations "user_account" and "gender") you add an artificial primary key (in the case exposed, primary key is a numeric field "id" but the primary key should be the combination of "user_account_id" and "gender_id").

Is there a technical reason to do that?

GOOD, I'M SATISFIED
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Thanks for the answer!

Satisfaction mark by Sergio González (IT teacher) 5 ár síðan
Answered
Adam Mościcki 5 ár síðan

Hello Sergio,

You are right, the primary key is an artifical (surrogate) primary key.

To be honest, I don't know the reason. 

The best way to get the answer is to ask directly in the article: https://www.vertabelo.com/blog/a-dating-app-data-model/

Hope this helps,

Adam

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