Hi what you are asking for seems more like multi-tenancy where the data is unique by store. If all of the data is valid for a single company or account you would need to use a different structure something like
The id is a record id so it must be unique.
The store_id is an identifier for which store is involved
The store_seq is a unique counter within each store. This you would need to manually calculate the current maximum value and increment.
There can only be one primary key in a table but the primary key can be a combination of two fields. Not sure what you are trying to do but I think you should look at your database model and think again.
Sounds like you need to back way up and learn how the foreign Keys work. And if you plan on using eloquent the documentation gives examples of how the Foreign Relations work and how to set them up.
@jlrdw How I said in the previous answer, I got this database already created when I enter in this company, I would love to reacreate it from scratch using eloquent