This my first post here, and I hope I will get the right answer I have already asked it on StackOverflow, but nobody has answered it.
I have question about inheritance representation in ERD-diagram. The following example: I have plane, and I have also two types of planes
I am confused which relationship to use ( 1-to-1 OR 1-to-Many). My DB teacher told me that I should use 1-to-1 relationship, But I have found on internet many examples use (1-to-Many) relationship instead of (1-to-1) . Check these images:
Personally I think that it should be (1-to-Many) because at a specific moment, in general, a Super Entity can have more than one child. So in our example here: a plane can be 3 persons-planes and 4 cargo-planes.
if not the I would just call it a plane and have a Dropdown selection what plane is it
also just to get you thinking hat
(1 to many)-(many to 1)
hope this help
See clear as mud
the aim is store once, not store multiple times
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