Database relationship between entities

Question

I have a question which I feel might be simple. I am relatively new to databases. I was looking at this conceptual ERD and saw these relationships between Seat -> Musical_Performance & Customer -> Booking Customer has 1..6 -> 0..* AND Musical_Performance 1..1 -> 100..1500 What relationships are these. Is Customer to Booking a many to many relationship and is Musical_Performance to Seat a one to many? Really confused about this and would appreciate anyone helping me out

Answer 1

You are right. Musical_Performance is one to many with seat . For each Musical Performance you can have multiple seats (100 to 1500).

Customer to Booking is many to many, each customer can have multiple booking (0 or more) but each booking can be connected just to 1-6 specific customers. This is probably comes to represent that you can book something for a family for example so one booking will have all of the family members customers.

Answer 2

WHat you have, looks like a Chen style ERD. These numbers can describe a minimum, or an optional:mandatory relationship. In this specific case, I'm not sure what they are relating to, but dig in:

https://www.smartdraw.com/entity-relationship-diagram/

and

https://www.lucidchart.com/pages/er-diagrams

and

https://www.oreilly.com/library/view/learning-mysql/0596008643/ch04s03.html

for more information.