Sign up ×  As we know a many to many association are shown by
two asterisks in both end of association. Now I have a
association between two entities "Good" and "Invoice" so Good
and Invoice have a many to many association but I want to show
the "count of each good" in each invoice on class diagram.  How
can I show it?  share|improve this question  2 Answers 2  up
vote 2 down vote accepted  You can use an association class as
depicted e.g. here:  Using a new class and two associations
inbetween like user1598390 described is valid as well. It
depends how you would like to see the relationship between your
entities. UML-wise association classes are probably more
concise. Regarding the implementation in a programming language
both solutions might even look the same (implemented with an
additional link object as most programming languages don't
support attributed links or pointers).  share|improve this
answer  Often times many to many associations indicate the need
for a third entity.  You need InvoiceDetail enti