ER Diagram : Understanding connections between relationship and entities

StackOverflow https://stackoverflow.com/questions/19696812

  •  02-07-2022
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题

I am trying to understand this diagram and after reading over PowerPoints and the Book I still don't see an answer to my question.

enter image description here

What is the difference between the single line and the double line connecting the relationship to the entities? Thank you.

有帮助吗？

解决方案

It signifies total participation of Movie in Acts_In. Also known as existence dependency.

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