diff options
Diffstat (limited to 'mediagoblin/db/migrations.py')
-rw-r--r-- | mediagoblin/db/migrations.py | 141 |
1 files changed, 140 insertions, 1 deletions
diff --git a/mediagoblin/db/migrations.py b/mediagoblin/db/migrations.py index 446f30df..8661c95a 100644 --- a/mediagoblin/db/migrations.py +++ b/mediagoblin/db/migrations.py @@ -36,7 +36,7 @@ from mediagoblin.db.extratypes import JSONEncoded, MutationDict from mediagoblin.db.migration_tools import ( RegisterMigration, inspect_table, replace_table_hack) from mediagoblin.db.models import (MediaEntry, Collection, MediaComment, User, - Privilege, Generator) + Privilege, Generator, GenericForeignKey) from mediagoblin.db.extratypes import JSONEncoded, MutationDict @@ -910,6 +910,14 @@ class ActivityIntermediator_R0(declarative_base()): id = Column(Integer, primary_key=True) type = Column(Unicode, nullable=False) + # These are needed for migration 29 + TYPES = { + "user": User, + "media": MediaEntry, + "comment": MediaComment, + "collection": Collection, + } + class Activity_R0(declarative_base()): __tablename__ = "core__activities" id = Column(Integer, primary_key=True) @@ -927,6 +935,7 @@ class Activity_R0(declarative_base()): ForeignKey(ActivityIntermediator_R0.id), nullable=True) + @RegisterMigration(24, MIGRATIONS) def activity_migration(db): """ @@ -1250,6 +1259,12 @@ def datetime_to_utc(db): # Commit this to the database db.commit() +## +# Migrations to handle migrating from activity specific foreign key to the +# new GenericForeignKey implementations. They have been split up to improve +# readability and minimise errors +## + class GenericModelReference_V0(declarative_base()): __tablename__ = "core__generic_model_reference" @@ -1263,4 +1278,128 @@ def create_generic_model_reference(db): GenericModelReference_V0.__table__.create(db.bind) db.commit() +@RegisterMigration(28, MIGRATIONS) +def add_foreign_key_fields(db): + """ + Add the fields for GenericForeignKey to the model under temporary name, + this is so that later a data migration can occur. They will be renamed to + the origional names. + """ + metadata = MetaData(bind=db.bind) + activity_table = inspect_table(metadata, "core__activities") + + # Create column and add to model. + object_column = Column("temp_object", Integer, GenericForeignKey()) + object_column.create(activity_table) + + target_column = Column("temp_target", Integer, GenericForeignKey()) + target_column.create(activity_table) + + # Commit this to the database + db.commit() + +@RegisterMigration(29, MIGRATIONS) +def migrate_data_foreign_keys(db): + """ + This will migrate the data from the old object and target attributes which + use the old ActivityIntermediator to the new temparay fields which use the + new GenericForeignKey. + """ + metadata = MetaData(bind=db.bind) + activity_table = inspect_table(metadata, "core__activities") + ai_table = inspect_table(metadata, "core__activity_intermediators") + gmr_table = inspect_table(metadata, "core__generic_model_reference") + + + # Iterate through all activities doing the migration per activity. + for activity in db.execute(activity_table.select()): + # First do the "Activity.object" migration to "Activity.temp_object" + # I need to get the object from the Activity, I can't use the old + # Activity.get_object as we're in a migration. + object_ai = db.execute(ai_table.select( + ai_table.c.id==activity.object + )).first() + + object_ai_type = ActivityIntermediator_R0.TYPES[object_ai.type] + object_ai_table = inspect_table(metadata, object_ai_type.__tablename__) + + activity_object = db.execute(object_ai_table.select( + object_ai_table.c.activity==object_ai.id + )).first() + + # now we need to create the GenericModelReference + object_gmr = db.execute(gmr_table.insert().values( + obj_pk=activity_object.id, + model_type=object_ai_type.__tablename__ + )) + + # Now set the ID of the GenericModelReference in the GenericForignKey + db.execute(activity_table.update().values( + temp_object=object_gmr.inserted_primary_key[0] + )) + + # Now do same process for "Activity.target" to "Activity.temp_target" + # not all Activities have a target so if it doesn't just skip the rest + # of this. + if activity.target is None: + continue + + # Now get the target for the activity. + target_ai = db.execute(ai_table.select( + ai_table.c.id==activity.target + )).first() + + target_ai_type = ActivityIntermediator_R0.TYPES[target_ai.type] + target_ai_table = inspect_table(metadata, target_ai_type.__tablename__) + + activity_target = db.execute(target_ai_table.select( + target_ai_table.c.activity==target_ai.id + )).first() + + # We now want to create the new target GenericModelReference + target_gmr = db.execute(gmr_table.insert().values( + obj_pk=activity_target.id, + model_type=target_ai_type.__tablename__ + )) + + # Now set the ID of the GenericModelReference in the GenericForignKey + db.execute(activity_table.update().values( + temp_object=target_gmr.inserted_primary_key[0] + )) + + # Commit to the database. + db.commit() + +@RegisterMigration(30, MIGRATIONS) +def rename_and_remove_object_and_target(db): + """ + Renames the new Activity.object and Activity.target fields and removes the + old ones. + """ + metadata = MetaData(bind=db.bind) + activity_table = inspect_table(metadata, "core__activities") + + # Firstly lets remove the old fields. + old_object_column = activity_table.columns["object"] + old_target_column = activity_table.columns["target"] + + # Drop the tables. + old_object_column.drop() + old_target_column.drop() + + # Now get the new columns. + new_object_column = activity_table.columns["temp_object"] + new_target_column = activity_table.columns["temp_target"] + + # rename them to the old names. + new_object_column.alter(name="object") + new_target_column.alter(name="target") + + # Commit the changes to the database. + db.commit() + + + + + |