For the two relations, Customer and Equipment:
There is a limited number of equipments (stock) and upon hiring I need to store the date of hire and the expected return date.
I sketched this:
Table Customer customer_id Table Equipment equip_id available_stock Table Hire_Equipment customer_id equip_id hiring_date expected_return_date
What I'm not sure about is what is the primary key of Hire_Equipment?
If it is customer_id and equip_id then the customer wont be able to hire the equipment again in the future?
Did I mis-designed the schema? do you suggest a better approach?