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Databases Querying Relational Databases Table Relationships One to One Relationships

Is ID in the Customer_Extension table both primary & foreign key?

Is ID in the Customer_Extension table both primary & foreign key?

2 Answers

Steven Parker
Steven Parker
216,148 Points

This was explained at about 1:46 in the video:

...we give it the same primary key as the original customer table.
This field, ID, is also the foreign key back to the customer table.

Kevin Gates
Kevin Gates
14,855 Points

In short, "Yes", it is both. But Steven Parker goes into more detail for how it works.