Commit 248fdb11 authored by Andrew Godwin's avatar Andrew Godwin
Browse files

Change FKs when what they point to changes

parent f3582a05

django/db/backends/schema.py

+20 −0
Original line number Diff line number Diff line
@@ -615,6 +615,11 @@ class BaseDatabaseSchemaEditor(object): 
                    "extra": "",

                }

            )

        # Type alteration on primary key? Then we need to alter the column

        # referring to us.

        rels_to_update = []

        if old_field.primary_key and new_field.primary_key and old_type != new_type:

            rels_to_update.extend(model._meta.get_all_related_objects())

        # Changed to become primary key?

        # Note that we don't detect unsetting of a PK, as we assume another field

        # will always come along and replace it.
@@ -641,6 +646,21 @@ class BaseDatabaseSchemaEditor(object): 
                    "columns": self.quote_name(new_field.column),

                }

            )

            # Update all referencing columns

            rels_to_update.extend(model._meta.get_all_related_objects())

        # Handle out type alters on the other end of rels from the PK stuff above

        for rel in rels_to_update:

            rel_db_params = rel.field.db_parameters(connection=self.connection)

            rel_type = rel_db_params['type']

            self.execute(

                self.sql_alter_column % {

                    "table": self.quote_name(rel.model._meta.db_table),

                    "changes": self.sql_alter_column_type % {

                        "column": self.quote_name(rel.field.column),

                        "type": rel_type,

                    }

                }

            )

        # Does it have a foreign key?

        if new_field.rel:

            self.execute(

django/db/migrations/autodetector.py

+70 −59
Original line number Diff line number Diff line
@@ -153,30 +153,46 @@ class MigrationAutodetector(object): 
            )

        # Changes within models

        kept_models = set(old_model_keys).intersection(new_model_keys)

        old_fields = set()

        new_fields = set()

        for app_label, model_name in kept_models:

            old_model_state = self.from_state.models[app_label, model_name]

            new_model_state = self.to_state.models[app_label, model_name]

            # Collect field changes for later global dealing with (so AddFields

            # always come before AlterFields even on separate models)

            old_fields.update((app_label, model_name, x) for x, y in old_model_state.fields)

            new_fields.update((app_label, model_name, x) for x, y in new_model_state.fields)

            # Unique_together changes

            if old_model_state.options.get("unique_together", set()) != new_model_state.options.get("unique_together", set()):

                self.add_to_migration(

                    app_label,

                    operations.AlterUniqueTogether(

                        name=model_name,

                        unique_together=new_model_state.options.get("unique_together", set()),

                    )

                )

        # New fields

            old_field_names = set(x for x, y in old_model_state.fields)

            new_field_names = set(x for x, y in new_model_state.fields)

            for field_name in new_field_names - old_field_names:

        for app_label, model_name, field_name in new_fields - old_fields:

            old_model_state = self.from_state.models[app_label, model_name]

            new_model_state = self.to_state.models[app_label, model_name]

            field = new_model_state.get_field_by_name(field_name)

            # Scan to see if this is actually a rename!

            field_dec = field.deconstruct()[1:]

            found_rename = False

                for removed_field_name in (old_field_names - new_field_names):

                    if old_model_state.get_field_by_name(removed_field_name).deconstruct()[1:] == field_dec:

                        if self.questioner.ask_rename(model_name, removed_field_name, field_name, field):

            for rem_app_label, rem_model_name, rem_field_name in (old_fields - new_fields):

                if rem_app_label == app_label and rem_model_name == model_name:

                    if old_model_state.get_field_by_name(rem_field_name).deconstruct()[1:] == field_dec:

                        if self.questioner.ask_rename(model_name, rem_field_name, field_name, field):

                            self.add_to_migration(

                                app_label,

                                operations.RenameField(

                                    model_name=model_name,

                                    old_name=removed_field_name,

                                    old_name=rem_field_name,

                                    new_name=field_name,

                                )

                            )

                            old_field_names.remove(removed_field_name)

                            new_field_names.remove(field_name)

                            old_fields.remove((rem_app_label, rem_model_name, rem_field_name))

                            new_fields.remove((app_label, model_name, field_name))

                            found_rename = True

                            break

            if found_rename:
@@ -204,7 +220,9 @@ class MigrationAutodetector(object): 
                    )

                )

        # Old fields

            for field_name in old_field_names - new_field_names:

        for app_label, model_name, field_name in old_fields - new_fields:

            old_model_state = self.from_state.models[app_label, model_name]

            new_model_state = self.to_state.models[app_label, model_name]

            self.add_to_migration(

                app_label,

                operations.RemoveField(
@@ -213,8 +231,10 @@ class MigrationAutodetector(object): 
                )

            )

        # The same fields

            for field_name in old_field_names.intersection(new_field_names):

        for app_label, model_name, field_name in old_fields.intersection(new_fields):

            # Did the field change?

            old_model_state = self.from_state.models[app_label, model_name]

            new_model_state = self.to_state.models[app_label, model_name]

            old_field_dec = old_model_state.get_field_by_name(field_name).deconstruct()

            new_field_dec = new_model_state.get_field_by_name(field_name).deconstruct()

            if old_field_dec != new_field_dec:
@@ -226,15 +246,6 @@ class MigrationAutodetector(object): 
                        field=new_model_state.get_field_by_name(field_name),

                    )

                )

            # unique_together changes

            if old_model_state.options.get("unique_together", set()) != new_model_state.options.get("unique_together", set()):

                self.add_to_migration(

                    app_label,

                    operations.AlterUniqueTogether(

                        name=model_name,

                        unique_together=new_model_state.options.get("unique_together", set()),

                    )

                )

        # Alright, now add internal dependencies

        for app_label, migrations in self.migrations.items():

            for m1, m2 in zip(migrations, migrations[1:]):

django/db/migrations/operations/fields.py

+5 −7
Original line number Diff line number Diff line
@@ -24,10 +24,9 @@ class AddField(Operation): 
        state.models[app_label, self.model_name.lower()].fields.append((self.name, field))



    def database_forwards(self, app_label, schema_editor, from_state, to_state):

        from_model = from_state.render().get_model(app_label, self.model_name)

        to_model = to_state.render().get_model(app_label, self.model_name)

        if router.allow_migrate(schema_editor.connection.alias, to_model):

            schema_editor.add_field(from_model, to_model._meta.get_field_by_name(self.name)[0])

            schema_editor.add_field(to_model, to_model._meta.get_field_by_name(self.name)[0])



    def database_backwards(self, app_label, schema_editor, from_state, to_state):

        from_model = from_state.render().get_model(app_label, self.model_name)
@@ -74,10 +73,9 @@ class RemoveField(Operation): 
            schema_editor.remove_field(from_model, from_model._meta.get_field_by_name(self.name)[0])



    def database_backwards(self, app_label, schema_editor, from_state, to_state):

        from_model = from_state.render().get_model(app_label, self.model_name)

        to_model = to_state.render().get_model(app_label, self.model_name)

        if router.allow_migrate(schema_editor.connection.alias, to_model):

            schema_editor.add_field(from_model, to_model._meta.get_field_by_name(self.name)[0])

            schema_editor.add_field(to_model, to_model._meta.get_field_by_name(self.name)[0])



    def describe(self):

        return "Remove field %s from %s" % (self.name, self.model_name)
@@ -109,7 +107,7 @@ class AlterField(Operation): 
        to_model = to_state.render().get_model(app_label, self.model_name)

        if router.allow_migrate(schema_editor.connection.alias, to_model):

            schema_editor.alter_field(

                from_model,

                to_model,

                from_model._meta.get_field_by_name(self.name)[0],

                to_model._meta.get_field_by_name(self.name)[0],

            )
@@ -155,7 +153,7 @@ class RenameField(Operation): 
        to_model = to_state.render().get_model(app_label, self.model_name)

        if router.allow_migrate(schema_editor.connection.alias, to_model):

            schema_editor.alter_field(

                from_model,

                to_model,

                from_model._meta.get_field_by_name(self.old_name)[0],

                to_model._meta.get_field_by_name(self.new_name)[0],

            )
@@ -165,7 +163,7 @@ class RenameField(Operation): 
        to_model = to_state.render().get_model(app_label, self.model_name)

        if router.allow_migrate(schema_editor.connection.alias, to_model):

            schema_editor.alter_field(

                from_model,

                to_model,

                from_model._meta.get_field_by_name(self.new_name)[0],

                to_model._meta.get_field_by_name(self.old_name)[0],

            )