I'm trying to enforce a uniqueness constraint on a table and I'm not sure the best way to go about it. I have two tables:
Child.parent_id is a foreign key referencing
Parent.id. I would like for
Child.name values to be unique, but only for members of
Child where the
Child.parent_id value is the same. That is,
child_one.parent_id == child_two.parent_id && child_one.name == child_two.nameshould be impossible
child_one.parent_id != child_two.parent_id && child_one.name == child_two.nameshould be possible.
If it's a great deal of trouble I may be willing to relax the second constraint and simply say that
Child.name must simply be globally unique, but I'm not very experienced with databases so I thought I would ask for advice.
I'm writing the application using Laravel, so the exact database technology is more of an implementation detail, but we happen to be using MySQL.
Thank you for any help.