I'm building a shift-scheduling app. I want to make a constraint in my database that prevents one human from being assigned to work two different jobs at the same time. In other words, if I schedule John Doe to mop bathrooms from 10 AM until 4 PM, some other manager will not be able to schedule John Doe for a 1 PM meeting. How can I do this with constraints? Would I need to write a trigger that does some 'select ... between ...' work? I know I could do this in the python application code I am using on top of postgres, but I really like putting as many constraints as possible in my data model. TIA Matt
