是否应该对所有表都使用用户的外键？

Question

I have four tables so far. They are named:

user, gang, gang_business, gang_members, gang_weapons

I am trying to figure out if I should use the primary key of either the "user" or "gang" table as foreign keys for the "gang_business", "gang_members", and "gang_weapons" table. The "gang" table has the user's primary key as a foreign key. I am trying to figure out which is the best route to take. Please give me your best advice and feedback. Thanks.

• user table: (user_id, user_name, user_email, user_password)
• gang table: (gang_id, user_id, gang_name, gang_color, gang_idelogy)
• gang_business:(business_id, user_id and/or gang_id, bar, restaurant,
  casino, etc)

Answer 1

It depends on the relations within the users and the gangs tables.

I would do it with this tables:

user: (id, name, email, password)

gang: (id, name, color, idelogy)

gang_members : (user_id, gang_id)

user_weapons: (user_id, weapon_id)

gang_business: (gang_id, business_id)

weapons: (id, name, ...)

business: (id, name, ...)

I would only prefix columns when they are foreign keys.

I suppose weapons belong to users and business belongs to gangs.

Answer 2

If only gang-sters can be a member of gang_business and gang_members, then you should use the PK of the gang table. You should not use the user PK because that is the super group, of which the gang table is a sub group of.