Question

I’m creating a website in which I will be managing users and their permissions. I am looking to implement user roles, and can’t seem to wrap my head around how things should work. I want to be able to assign a user a certain role, and have each role contain one to several permissions that can be read easily by my script. Just want to know how I should go about setting up my database to do this easily and efficiently.

In my head I picture 3 tables (users, roles, and permissions). I could give each user a role id that joins the roles table, I just don’t know how I can link roles to several permissions.

Answer 1

I just don’t know how I can link roles
to several permissions.

You use a join table: role_id and permission_id to identify what permissions are associated with which roles

EDIT:

Example tables

ROLE Table

Role_ID Role_Name
1       Standard User
2       Super User
3       Guest

PERMISSION Table

Permission_ID Permission_Name
1             View User List
2             Update Own User Account
3             Update Any User Account

ROLE_PERMISSION Table

Role_ID Permission_ID
1       1    // Role 1 (Standard User) grants View User List
1       2    //        and Update Own User Account
2       1    // Role 2 (Super User) grants View User List,
2       2    //        Update Own User Account,
2       3    //        and Update Any User Account
3       1    // Role 3 (Guest) grants View User List

Listing the permissions for a specified Role_ID

select R.role_id,
       P.permission_id,
       P.permission_name
  from role R,
       permission P,
       role_permission RP
 where RP.permission_id = P.permission_id
   and RP.role_id = R.role_id
   and R.role_id = 1