Hi,

I am implementing a small database(university Project) and i am facing the following problem.

I created a class diagram where i have a class

Train {Id, Name, Details}

And a class

RollingStock

which is than generalized in Locomotive and FreightWagon.

A train is Composed by multiple RollingStock at a certain time(on different days the rolling

stock will compose a different train).

I represented the relationship train - rolling stock as a diamond filled (UML) but still I

have a many to many relationship between the two tables.

so i guess i have to create an additional table to solve the many to many relationship

train_RollingStock.

but how do i represent the Composition?

Can i still use the filled diamond? If yes on which side?

Thanks