usertorole

User-to-role, often implemented as a mapping such as a user_to_role table, is a concept in access control that connects individual users to one or more roles. A role represents a defined set of permissions, and assigning a role to a user grants those permissions.

In typical implementations, the relationship is many-to-many: a user can have multiple roles, and a role can be assigned to many users. A join structure, frequently named user_to_role or user_roles, stores associations with fields such as user_id, role_id, assigned_at, expires_at, and an active flag. Some systems also record the source of the assignment (manual, automatic, or workflow-driven).

Roles encapsulate permissions, which are the specific actions authorized within a system. Roles can participate in hierarchies, where a role inherits permissions from one or more parent roles, though not all systems use hierarchies. The mapping supports lifecycle operations such as creation, assignment, revocation, and periodic review to maintain appropriate access levels.

Common use cases include enterprise identity and access management, cloud IAM, and application-level authorization. For example, a user may be granted the Editor role to modify content or the Admin role to perform high-privilege operations. Just-in-time or temporary elevations can also be implemented by time-bounding the role assignment.

Key considerations include enforcing least privilege, auditing changes to user_to_role mappings, and ensuring timely revocation when roles change or users depart. See also RBAC, ABAC, ACL, and IAM.