Model definition for LMSUserAssignmentMembership

This is mostly a duplicate of AssignmentMembership but that table has a
composed primary key that makes changes to the schema more challenging.

The new table continues the same line of work as LMSCourseMembership and
similar tables.

It also includes the `lti_v11_lis_result_sourcedid` column to store the
grading ID of the user in one assignment to enable participation grading
in LTI1.1

lms/models/__init__.py

@@ -2,7 +2,10 @@
 from lms.models.application_instance import ApplicationInstance, ApplicationSettings
 from lms.models.assignment import Assignment, AutoGradingConfig
 from lms.models.assignment_grouping import AssignmentGrouping
-from lms.models.assignment_membership import AssignmentMembership
+from lms.models.assignment_membership import (
+    AssignmentMembership,
+    LMSUserAssignmentMembership,
+)
 from lms.models.course_groups_exported_from_h import CourseGroupsExportedFromH
 from lms.models.dashboard_admin import DashboardAdmin
 from lms.models.event import Event, EventData, EventType, EventUser

lms/models/assignment_membership.py

@@ -1,4 +1,5 @@
-import sqlalchemy as sa
+from sqlalchemy import ForeignKey, UniqueConstraint
+from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from lms.db import Base
 from lms.models._mixins import CreatedUpdatedMixin
@@ -9,29 +10,52 @@ class AssignmentMembership(CreatedUpdatedMixin, Base):
 
     __tablename__ = "assignment_membership"
 
-    assignment_id = sa.Column(
-        sa.Integer(),
-        sa.ForeignKey("assignment.id", ondelete="cascade"),
-        primary_key=True,
-        index=True,
+    assignment_id: Mapped[int] = mapped_column(
+        ForeignKey("assignment.id", ondelete="cascade"), primary_key=True, index=True
     )
-    assignment = sa.orm.relationship("Assignment", foreign_keys=[assignment_id])
+    assignment = relationship("Assignment", foreign_keys=[assignment_id])
     """The assignment the user is a member of."""
 
-    user_id = sa.Column(
-        sa.Integer(),
-        sa.ForeignKey("user.id", ondelete="cascade"),
-        primary_key=True,
-        index=True,
+    user_id: Mapped[int] = mapped_column(
+        ForeignKey("user.id", ondelete="cascade"), primary_key=True, index=True
     )
-    user = sa.orm.relationship("User", foreign_keys=[user_id])
+    user = relationship("User", foreign_keys=[user_id])
     """The user who is a member."""
 
-    lti_role_id = sa.Column(
-        sa.Integer(),
-        sa.ForeignKey("lti_role.id", ondelete="cascade"),
-        primary_key=True,
+    lti_role_id: Mapped[int] = mapped_column(
+        ForeignKey("lti_role.id", ondelete="cascade"), primary_key=True, index=True
+    )
+    lti_role = relationship("LTIRole", foreign_keys=[lti_role_id])
+    """What role the user plays in the assignment."""
+
+
+class LMSUserAssignmentMembership(CreatedUpdatedMixin, Base):
+    """Record of LMSUser that have launched one particular assignment.
+
+    One row for each assignment, user and role.
+    """
+
+    __tablename__ = "lms_user_assignment_membership"
+    __table_args__ = (UniqueConstraint("assignment_id", "lms_user_id", "lti_role_id"),)
+
+    id: Mapped[int] = mapped_column(autoincrement=True, primary_key=True)
+
+    assignment_id: Mapped[int] = mapped_column(
+        ForeignKey("assignment.id", ondelete="cascade"), index=True
+    )
+    assignment = relationship("Assignment", foreign_keys=[assignment_id])
+
+    lms_user_id: Mapped[int] = mapped_column(
+        ForeignKey("lms_user.id", ondelete="cascade"), index=True
+    )
+    lms_user = relationship("LMSUser", foreign_keys=[lms_user_id])
+
+    lti_role_id: Mapped[int] = mapped_column(
+        ForeignKey("lti_role.id", ondelete="cascade"),
         index=True,
     )
-    lti_role = sa.orm.relationship("LTIRole", foreign_keys=[lti_role_id])
+    lti_role = relationship("LTIRole", foreign_keys=[lti_role_id])
     """What role the user plays in the assignment."""
+
+    lti_v11_lis_result_sourcedid: Mapped[str | None] = mapped_column()
+    """LTI's lis_result_sourcedid, the relevant ID of one user in one assigment for the LTI1.1 grading API."""

tests/factories/__init__.py

@@ -6,7 +6,10 @@
 from tests.factories.application_instance import ApplicationInstance
 from tests.factories.assignment import Assignment
 from tests.factories.assignment_grouping import AssignmentGrouping
-from tests.factories.assignment_membership import AssignmentMembership
+from tests.factories.assignment_membership import (
+    AssignmentMembership,
+    LMSUserAssignmentMembership,
+)
 from tests.factories.attributes import (
     ACCESS_TOKEN,
     H_DISPLAY_NAME,

tests/factories/assignment_membership.py

@@ -6,3 +6,7 @@
 AssignmentMembership = make_factory(
     models.AssignmentMembership, FACTORY_CLASS=SQLAlchemyModelFactory
 )
+
+LMSUserAssignmentMembership = make_factory(
+    models.LMSUserAssignmentMembership, FACTORY_CLASS=SQLAlchemyModelFactory
+)