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Why is Booking entity not weak?

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#1

Hi!

Why is Booking entity not weak as it had no meaning without Passenger or Flight entities?

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Course: https://www.educative.io/collection/10370001/5119687241236480
Lesson: https://www.educative.io/collection/page/10370001/5119687241236480/5615020173950976

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#2

Hi @Ingela,
Booking can not be treated as a weak entity. We can call it an intermediate hidden entity because there is a many-to-many relationship between Flight and Passenger.
Each booking must be associated with a particular passenger and flight, and the booking entity participates totally in the relationships with these entities. When we reduce this ERD to tables, the booking entity will become a separate table, and primary keys from PAssenger and Flight will become foreign keys in the booking table.