Best Role-Based Access Control (RBAC) database model

Here is a simple diagram to illustrate Amr Mostafa's excellent answer

To my rather basic knowledge in that area, the basic actors of an RBAC are:

• Resources.
• Permissions.
• Users.
• Roles (i.e. Groups).

Resources <- require -> (one or many) Permissions.

Roles <- are collections of -> (one or many) Permissions.

Users <- can have -> (one or many) Roles.

The tables for such a model would be:

• permission
• role
• user
• role_permission
• user_role

Now you might want to include resources here as well if you want users of your application to be able to configure which permissions a resource need. But I never needed that. Hope that helps.