CohortMemberships Migrations

These are the migrations needed for CohortMembership to function.
0005 establishes the table, 0006 will be used to move existing data
into the table as needed.

Per product guidance, we can just arbitrarily reassign problem users.
Implementing that decision, as well as the remainder of the data migration.

Also including a short script to re-run the 0006 migration after code changes
are live, to prevent a potential issue where the database become out-of-sync.

openedx/core/djangoapps/course_groups/migrations/0005_cohort_membership.py

@@ -0,0 +1,109 @@
+# -*- coding: utf-8 -*-
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Adding model 'CohortMembership'
+        db.create_table('course_groups_cohortmembership', (
+            ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('course_user_group', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['course_groups.CourseUserGroup'])),
+            ('user', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['auth.User'])),
+            ('course_id', self.gf('xmodule_django.models.CourseKeyField')(max_length=255)),
+        ))
+        db.send_create_signal('course_groups', ['CohortMembership'])
+
+        # Adding unique constraint on 'CohortMembership', fields ['user', 'course_id']
+        db.create_unique('course_groups_cohortmembership', ['user_id', 'course_id'])
+
+
+    def backwards(self, orm):
+        # Removing unique constraint on 'CohortMembership', fields ['user', 'course_id']
+        db.delete_unique('course_groups_cohortmembership', ['user_id', 'course_id'])
+
+        # Deleting model 'CohortMembership'
+        db.delete_table('course_groups_cohortmembership')
+
+
+    models = {
+        'auth.group': {
+            'Meta': {'object_name': 'Group'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '80'}),
+            'permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'})
+        },
+        'auth.permission': {
+            'Meta': {'ordering': "('content_type__app_label', 'content_type__model', 'codename')", 'unique_together': "(('content_type', 'codename'),)", 'object_name': 'Permission'},
+            'codename': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'auth.user': {
+            'Meta': {'object_name': 'User'},
+            'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
+            'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'groups': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Group']", 'symmetrical': 'False', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'is_staff': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'is_superuser': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'last_login': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'password': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
+            'user_permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'}),
+            'username': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'})
+        },
+        'contenttypes.contenttype': {
+            'Meta': {'ordering': "('name',)", 'unique_together': "(('app_label', 'model'),)", 'object_name': 'ContentType', 'db_table': "'django_content_type'"},
+            'app_label': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'model': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        'course_groups.cohortmembership': {
+            'Meta': {'unique_together': "(('user', 'course_id'),)", 'object_name': 'CohortMembership'},
+            'course_id': ('xmodule_django.models.CourseKeyField', [], {'max_length': '255'}),
+            'course_user_group': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['course_groups.CourseUserGroup']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'user': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.User']"})
+        },
+        'course_groups.coursecohort': {
+            'Meta': {'object_name': 'CourseCohort'},
+            'assignment_type': ('django.db.models.fields.CharField', [], {'default': "'manual'", 'max_length': '20'}),
+            'course_user_group': ('django.db.models.fields.related.OneToOneField', [], {'related_name': "'cohort'", 'unique': 'True', 'to': "orm['course_groups.CourseUserGroup']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'})
+        },
+        'course_groups.coursecohortssettings': {
+            'Meta': {'object_name': 'CourseCohortsSettings'},
+            '_cohorted_discussions': ('django.db.models.fields.TextField', [], {'null': 'True', 'db_column': "'cohorted_discussions'", 'blank': 'True'}),
+            'always_cohort_inline_discussions': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'course_id': ('xmodule_django.models.CourseKeyField', [], {'unique': 'True', 'max_length': '255', 'db_index': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_cohorted': ('django.db.models.fields.BooleanField', [], {'default': 'False'})
+        },
+        'course_groups.courseusergroup': {
+            'Meta': {'unique_together': "(('name', 'course_id'),)", 'object_name': 'CourseUserGroup'},
+            'course_id': ('xmodule_django.models.CourseKeyField', [], {'max_length': '255', 'db_index': 'True'}),
+            'group_type': ('django.db.models.fields.CharField', [], {'max_length': '20'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
+            'users': ('django.db.models.fields.related.ManyToManyField', [], {'db_index': 'True', 'related_name': "'course_groups'", 'symmetrical': 'False', 'to': "orm['auth.User']"})
+        },
+        'course_groups.courseusergrouppartitiongroup': {
+            'Meta': {'object_name': 'CourseUserGroupPartitionGroup'},
+            'course_user_group': ('django.db.models.fields.related.OneToOneField', [], {'to': "orm['course_groups.CourseUserGroup']", 'unique': 'True'}),
+            'created_at': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
+            'group_id': ('django.db.models.fields.IntegerField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'partition_id': ('django.db.models.fields.IntegerField', [], {}),
+            'updated_at': ('django.db.models.fields.DateTimeField', [], {'auto_now': 'True', 'blank': 'True'})
+        }
+    }
+
+    complete_apps = ['course_groups']

openedx/core/djangoapps/course_groups/migrations/0006_cohort_membership_data_migrate.py

@@ -0,0 +1,138 @@
+# -*- coding: utf-8 -*-
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import DataMigration
+from django.db import models, IntegrityError, transaction
+
+
+class Migration(DataMigration):
+
+    def forwards(self, orm):
+        # Matches CourseUserGroup.COHORT
+        cohort_type = 'cohort'
+
+        for cohort_group in orm.CourseUserGroup.objects.all():
+            for user in cohort_group.users.all():
+                current_course_groups = orm.CourseUserGroup.objects.filter(
+                    course_id=cohort_group.course_id,
+                    users__id=user.id,
+                    group_type=cohort_type
+                )
+                current_user_groups = user.course_groups.filter(
+                    course_id=cohort_group.course_id,
+                    group_type=cohort_type
+                )
+
+                unioned_set = set(current_course_groups).union(set(current_user_groups))
+
+                # Per product guidance, fix problem users by arbitrarily choosing a single membership to retain
+                arbitrary_cohort_to_keep = unioned_set.pop()
+
+                try:
+                    membership = orm.CohortMembership(
+                        course_user_group=arbitrary_cohort_to_keep,
+                        user=user,
+                        course_id=arbitrary_cohort_to_keep.course_id
+                    )
+                    membership.save()
+                except IntegrityError:
+                    # It's possible a user already has a conflicting entry in the db. Treat that as correct.
+                    unioned_set.add(arbitrary_cohort_to_keep)
+                    try:
+                        valid_membership = orm.CohortMembership.objects.get(
+                            course_id = cohort_group.course_id,
+                            user__id=user.id
+                        )
+                        actual_cohort_to_keep = orm.CourseUserGroup.objects.get(
+                            id=valid_membership.course_user_group.id
+                        )
+                        unioned_set.remove(actual_cohort_to_keep)
+                    except KeyError:
+                        actual_cohort_to_keep.users.add(user)
+
+                for cohort_itr in unioned_set:
+                    cohort_itr.users.remove(user)
+                    user.course_groups.remove(cohort_itr)
+
+    def backwards(self, orm):
+        # A backwards migration just means dropping the table, which 0005 handles in its backwards() method
+        pass
+
+    models = {
+        'auth.group': {
+            'Meta': {'object_name': 'Group'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '80'}),
+            'permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'})
+        },
+        'auth.permission': {
+            'Meta': {'ordering': "('content_type__app_label', 'content_type__model', 'codename')", 'unique_together': "(('content_type', 'codename'),)", 'object_name': 'Permission'},
+            'codename': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'auth.user': {
+            'Meta': {'object_name': 'User'},
+            'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
+            'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'groups': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Group']", 'symmetrical': 'False', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'is_staff': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'is_superuser': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'last_login': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'password': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
+            'user_permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'}),
+            'username': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'})
+        },
+        'contenttypes.contenttype': {
+            'Meta': {'ordering': "('name',)", 'unique_together': "(('app_label', 'model'),)", 'object_name': 'ContentType', 'db_table': "'django_content_type'"},
+            'app_label': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'model': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        'course_groups.cohortmembership': {
+            'Meta': {'unique_together': "(('user', 'course_id'),)", 'object_name': 'CohortMembership'},
+            'course_id': ('xmodule_django.models.CourseKeyField', [], {'max_length': '255'}),
+            'course_user_group': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['course_groups.CourseUserGroup']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'user': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.User']"})
+        },
+        'course_groups.coursecohort': {
+            'Meta': {'object_name': 'CourseCohort'},
+            'assignment_type': ('django.db.models.fields.CharField', [], {'default': "'manual'", 'max_length': '20'}),
+            'course_user_group': ('django.db.models.fields.related.OneToOneField', [], {'related_name': "'cohort'", 'unique': 'True', 'to': "orm['course_groups.CourseUserGroup']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'})
+        },
+        'course_groups.coursecohortssettings': {
+            'Meta': {'object_name': 'CourseCohortsSettings'},
+            '_cohorted_discussions': ('django.db.models.fields.TextField', [], {'null': 'True', 'db_column': "'cohorted_discussions'", 'blank': 'True'}),
+            'always_cohort_inline_discussions': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'course_id': ('xmodule_django.models.CourseKeyField', [], {'unique': 'True', 'max_length': '255', 'db_index': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_cohorted': ('django.db.models.fields.BooleanField', [], {'default': 'False'})
+        },
+        'course_groups.courseusergroup': {
+            'Meta': {'unique_together': "(('name', 'course_id'),)", 'object_name': 'CourseUserGroup'},
+            'course_id': ('xmodule_django.models.CourseKeyField', [], {'max_length': '255', 'db_index': 'True'}),
+            'group_type': ('django.db.models.fields.CharField', [], {'max_length': '20'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
+            'users': ('django.db.models.fields.related.ManyToManyField', [], {'db_index': 'True', 'related_name': "'course_groups'", 'symmetrical': 'False', 'to': "orm['auth.User']"})
+        },
+        'course_groups.courseusergrouppartitiongroup': {
+            'Meta': {'object_name': 'CourseUserGroupPartitionGroup'},
+            'course_user_group': ('django.db.models.fields.related.OneToOneField', [], {'to': "orm['course_groups.CourseUserGroup']", 'unique': 'True'}),
+            'created_at': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
+            'group_id': ('django.db.models.fields.IntegerField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'partition_id': ('django.db.models.fields.IntegerField', [], {}),
+            'updated_at': ('django.db.models.fields.DateTimeField', [], {'auto_now': 'True', 'blank': 'True'})
+        }
+    }
+
+    complete_apps = ['course_groups']

openedx/core/djangoapps/course_groups/migrations/rerun_0006.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+if [ $# -eq 0 ]; then
+    echo "$0: usage: rerun_0006.sh <arguments>. At minimum, '--settings=<environment>' is expected."
+    exit 1
+fi
+
+./manage.py lms migrate course_groups 0005 --fake "$@"
+./manage.py lms migrate course_groups 0006 "$@"

openedx/core/djangoapps/course_groups/models.py

@@ -37,7 +37,7 @@ class CourseUserGroup(models.Model):
 
     # For now, only have group type 'cohort', but adding a type field to support
     # things like 'question_discussion', 'friends', 'off-line-class', etc
-    COHORT = 'cohort'
+    COHORT = 'cohort'  # If changing this string, update it in migration 0006.forwards() as well
     GROUP_TYPE_CHOICES = ((COHORT, 'Cohort'),)
     group_type = models.CharField(max_length=20, choices=GROUP_TYPE_CHOICES)