Chen notation to crow's foot

Question

How do I illustrate relationships which has an attribute in chen notation to crows foot notation?

Example:

There is an attribute "quantity" in the relation. How do I draw that in crow's foot notation? Thanks

Answer 1

You want an intersection entitiy:

Intersection entities are used in the resolution of a many to many relationship. This resolution is done in order to store additional information which doesn’t fit into the attribute list of either entity in the M:M relationship.

See the Class entity below.

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