Question

I am working on a django model and not being a database expert I could use some advice. I essentially have a model which contains a many to many relationship with another model. But I need to store unique values for each relationship each time I include something.

So for instance in chemistry you may have many elements that include hydrogen, but each element has a unique amount of hydrogen in it. So for instance a water entry would be connected to hydrogen and oxygen and the amount would be two hydrogen atoms and one oxygen.

I want hydrogen and water in this scenario to be stored in the database as elements, so I can query against them for other elements using them.

What is the best way to model this?

Thanks!

Answer 1

Read the documentaion here and pay close attention to the Beatles example, it’s exactly what you need.

Person -> Element

Group -> Chemical_Compound

Membership -> Element_2_Chemical

Element_2_Chemical should have an int field which details how many elements you have in each chemical compound.