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What is the relationship between a Customer entity and an Order entity, where a customer entry will be present in the Customer entity only if they have made an order?
Suggested Answer: D
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The relationship between a Customer entity and an Order entity, where a customer entry will be present in the Customer entity only if they have made an order, is a zero-to-one relationship. This means that for each record in the Order entity, there can be either zero or one record in the Customer entity that is related to it. This implies that the Order entity is optional for the Customer entity, and the Customer entity is mandatory for the Order entity12 Reference: 1: A Guide to the Entity Relationship Diagram (ERD) - Database Star 2: Developing an Application - Oracle
5 comments · newest first
MA
Marcelle
3 days ago
It's definitely one-to-many. A customer can have multiple orders.
VI
Vincenza
8 days ago
I believe it’s many-to-many because customers can have multiple orders and orders can belong to multiple customers, but I might be mixing it up with another topic.
LA
Latosha
13 days ago
I’m leaning towards zero-to-one since a customer might not have placed an order yet, but I'm not confident about that.
SH
Sharen
18 days ago
I remember practicing a similar question, and I think it was about how customers relate to their orders. It feels like it could be one-to-one, but that doesn't seem right.
VA
Val
23 days ago
I think it's one-to-many because a customer can make multiple orders, but I'm not entirely sure.