Loading django/db/migrations/executor.py 0 → 100644 +68 −0 Original line number Diff line number Diff line from .loader import MigrationLoader from .recorder import MigrationRecorder class MigrationExecutor(object): """ End-to-end migration execution - loads migrations, and runs them up or down to a specified set of targets. """ def __init__(self, connection): self.connection = connection self.loader = MigrationLoader(self.connection) self.recorder = MigrationRecorder(self.connection) def migration_plan(self, targets): """ Given a set of targets, returns a list of (Migration instance, backwards?). """ plan = [] applied = self.recorder.applied_migrations() for target in targets: # If the migration is already applied, do backwards mode, # otherwise do forwards mode. if target in applied: for migration in self.loader.graph.backwards_plan(target)[:-1]: if migration in applied: plan.append((self.loader.graph.nodes[migration], True)) applied.remove(migration) else: for migration in self.loader.graph.forwards_plan(target): if migration not in applied: plan.append((self.loader.graph.nodes[migration], False)) applied.add(migration) return plan def migrate(self, targets): """ Migrates the database up to the given targets. """ plan = self.migration_plan(targets) for migration, backwards in plan: if not backwards: self.apply_migration(migration) else: self.unapply_migration(migration) def apply_migration(self, migration): """ Runs a migration forwards. """ print "Applying %s" % migration with self.connection.schema_editor() as schema_editor: project_state = self.loader.graph.project_state((migration.app_label, migration.name), at_end=False) migration.apply(project_state, schema_editor) self.recorder.record_applied(migration.app_label, migration.name) print "Finished %s" % migration def unapply_migration(self, migration): """ Runs a migration backwards. """ print "Unapplying %s" % migration with self.connection.schema_editor() as schema_editor: project_state = self.loader.graph.project_state((migration.app_label, migration.name), at_end=False) migration.unapply(project_state, schema_editor) self.recorder.record_unapplied(migration.app_label, migration.name) print "Finished %s" % migration django/db/migrations/migration.py +48 −0 Original line number Diff line number Diff line Loading @@ -36,6 +36,17 @@ class Migration(object): self.name = name self.app_label = app_label def __eq__(self, other): if not isinstance(other, Migration): return False return (self.name == other.name) and (self.app_label == other.app_label) def __ne__(self, other): return not (self == other) def __repr__(self): return "<Migration %s.%s>" % (self.app_label, self.name) def mutate_state(self, project_state): """ Takes a ProjectState and returns a new one with the migration's Loading @@ -45,3 +56,40 @@ class Migration(object): for operation in self.operations: operation.state_forwards(self.app_label, new_state) return new_state def apply(self, project_state, schema_editor): """ Takes a project_state representing all migrations prior to this one and a schema_editor for a live database and applies the migration in a forwards order. Returns the resulting project state for efficient re-use by following Migrations. """ for operation in self.operations: # Get the state after the operation has run new_state = project_state.clone() operation.state_forwards(self.app_label, new_state) # Run the operation operation.database_forwards(self.app_label, schema_editor, project_state, new_state) # Switch states project_state = new_state return project_state def unapply(self, project_state, schema_editor): """ Takes a project_state representing all migrations prior to this one and a schema_editor for a live database and applies the migration in a reverse order. """ # We need to pre-calculate the stack of project states to_run = [] for operation in self.operations: new_state = project_state.clone() operation.state_forwards(self.app_label, new_state) to_run.append((operation, project_state, new_state)) project_state = new_state # Now run them in reverse to_run.reverse() for operation, to_state, from_state in to_run: operation.database_backwards(self.app_label, schema_editor, from_state, to_state) django/db/migrations/operations/fields.py +8 −8 Original line number Diff line number Diff line Loading @@ -16,13 +16,13 @@ class AddField(Operation): def database_forwards(self, app_label, schema_editor, from_state, to_state): app_cache = to_state.render() model = app_cache.get_model(app_label, self.name) schema_editor.add_field(model, model._meta.get_field_by_name(self.name)) model = app_cache.get_model(app_label, self.model_name) schema_editor.add_field(model, model._meta.get_field_by_name(self.name)[0]) def database_backwards(self, app_label, schema_editor, from_state, to_state): app_cache = from_state.render() model = app_cache.get_model(app_label, self.name) schema_editor.remove_field(model, model._meta.get_field_by_name(self.name)) model = app_cache.get_model(app_label, self.model_name) schema_editor.remove_field(model, model._meta.get_field_by_name(self.name)[0]) class RemoveField(Operation): Loading @@ -43,10 +43,10 @@ class RemoveField(Operation): def database_forwards(self, app_label, schema_editor, from_state, to_state): app_cache = from_state.render() model = app_cache.get_model(app_label, self.name) schema_editor.remove_field(model, model._meta.get_field_by_name(self.name)) model = app_cache.get_model(app_label, self.model_name) schema_editor.remove_field(model, model._meta.get_field_by_name(self.name)[0]) def database_backwards(self, app_label, schema_editor, from_state, to_state): app_cache = to_state.render() model = app_cache.get_model(app_label, self.name) schema_editor.add_field(model, model._meta.get_field_by_name(self.name)) model = app_cache.get_model(app_label, self.model_name) schema_editor.add_field(model, model._meta.get_field_by_name(self.name)[0]) tests/migrations/migrations/0002_second.py +1 −1 Original line number Diff line number Diff line Loading @@ -11,7 +11,7 @@ class Migration(migrations.Migration): migrations.RemoveField("Author", "silly_field"), migrations.AddField("Author", "important", models.BooleanField()), migrations.AddField("Author", "rating", models.IntegerField(default=0)), migrations.CreateModel( "Book", Loading tests/migrations/test_executor.py 0 → 100644 +35 −0 Original line number Diff line number Diff line from django.test import TransactionTestCase from django.db import connection from django.db.migrations.executor import MigrationExecutor class ExecutorTests(TransactionTestCase): """ Tests the migration executor (full end-to-end running). Bear in mind that if these are failing you should fix the other test failures first, as they may be propagating into here. """ def test_run(self): """ Tests running a simple set of migrations. """ executor = MigrationExecutor(connection) # Let's look at the plan first and make sure it's up to scratch plan = executor.migration_plan([("migrations", "0002_second")]) self.assertEqual( plan, [ (executor.loader.graph.nodes["migrations", "0001_initial"], False), (executor.loader.graph.nodes["migrations", "0002_second"], False), ], ) # Were the tables there before? self.assertNotIn("migrations_author", connection.introspection.get_table_list(connection.cursor())) self.assertNotIn("migrations_book", connection.introspection.get_table_list(connection.cursor())) # Alright, let's try running it executor.migrate([("migrations", "0002_second")]) # Are the tables there now? self.assertIn("migrations_author", connection.introspection.get_table_list(connection.cursor())) self.assertIn("migrations_book", connection.introspection.get_table_list(connection.cursor())) Loading
django/db/migrations/executor.py 0 → 100644 +68 −0 Original line number Diff line number Diff line from .loader import MigrationLoader from .recorder import MigrationRecorder class MigrationExecutor(object): """ End-to-end migration execution - loads migrations, and runs them up or down to a specified set of targets. """ def __init__(self, connection): self.connection = connection self.loader = MigrationLoader(self.connection) self.recorder = MigrationRecorder(self.connection) def migration_plan(self, targets): """ Given a set of targets, returns a list of (Migration instance, backwards?). """ plan = [] applied = self.recorder.applied_migrations() for target in targets: # If the migration is already applied, do backwards mode, # otherwise do forwards mode. if target in applied: for migration in self.loader.graph.backwards_plan(target)[:-1]: if migration in applied: plan.append((self.loader.graph.nodes[migration], True)) applied.remove(migration) else: for migration in self.loader.graph.forwards_plan(target): if migration not in applied: plan.append((self.loader.graph.nodes[migration], False)) applied.add(migration) return plan def migrate(self, targets): """ Migrates the database up to the given targets. """ plan = self.migration_plan(targets) for migration, backwards in plan: if not backwards: self.apply_migration(migration) else: self.unapply_migration(migration) def apply_migration(self, migration): """ Runs a migration forwards. """ print "Applying %s" % migration with self.connection.schema_editor() as schema_editor: project_state = self.loader.graph.project_state((migration.app_label, migration.name), at_end=False) migration.apply(project_state, schema_editor) self.recorder.record_applied(migration.app_label, migration.name) print "Finished %s" % migration def unapply_migration(self, migration): """ Runs a migration backwards. """ print "Unapplying %s" % migration with self.connection.schema_editor() as schema_editor: project_state = self.loader.graph.project_state((migration.app_label, migration.name), at_end=False) migration.unapply(project_state, schema_editor) self.recorder.record_unapplied(migration.app_label, migration.name) print "Finished %s" % migration
django/db/migrations/migration.py +48 −0 Original line number Diff line number Diff line Loading @@ -36,6 +36,17 @@ class Migration(object): self.name = name self.app_label = app_label def __eq__(self, other): if not isinstance(other, Migration): return False return (self.name == other.name) and (self.app_label == other.app_label) def __ne__(self, other): return not (self == other) def __repr__(self): return "<Migration %s.%s>" % (self.app_label, self.name) def mutate_state(self, project_state): """ Takes a ProjectState and returns a new one with the migration's Loading @@ -45,3 +56,40 @@ class Migration(object): for operation in self.operations: operation.state_forwards(self.app_label, new_state) return new_state def apply(self, project_state, schema_editor): """ Takes a project_state representing all migrations prior to this one and a schema_editor for a live database and applies the migration in a forwards order. Returns the resulting project state for efficient re-use by following Migrations. """ for operation in self.operations: # Get the state after the operation has run new_state = project_state.clone() operation.state_forwards(self.app_label, new_state) # Run the operation operation.database_forwards(self.app_label, schema_editor, project_state, new_state) # Switch states project_state = new_state return project_state def unapply(self, project_state, schema_editor): """ Takes a project_state representing all migrations prior to this one and a schema_editor for a live database and applies the migration in a reverse order. """ # We need to pre-calculate the stack of project states to_run = [] for operation in self.operations: new_state = project_state.clone() operation.state_forwards(self.app_label, new_state) to_run.append((operation, project_state, new_state)) project_state = new_state # Now run them in reverse to_run.reverse() for operation, to_state, from_state in to_run: operation.database_backwards(self.app_label, schema_editor, from_state, to_state)
django/db/migrations/operations/fields.py +8 −8 Original line number Diff line number Diff line Loading @@ -16,13 +16,13 @@ class AddField(Operation): def database_forwards(self, app_label, schema_editor, from_state, to_state): app_cache = to_state.render() model = app_cache.get_model(app_label, self.name) schema_editor.add_field(model, model._meta.get_field_by_name(self.name)) model = app_cache.get_model(app_label, self.model_name) schema_editor.add_field(model, model._meta.get_field_by_name(self.name)[0]) def database_backwards(self, app_label, schema_editor, from_state, to_state): app_cache = from_state.render() model = app_cache.get_model(app_label, self.name) schema_editor.remove_field(model, model._meta.get_field_by_name(self.name)) model = app_cache.get_model(app_label, self.model_name) schema_editor.remove_field(model, model._meta.get_field_by_name(self.name)[0]) class RemoveField(Operation): Loading @@ -43,10 +43,10 @@ class RemoveField(Operation): def database_forwards(self, app_label, schema_editor, from_state, to_state): app_cache = from_state.render() model = app_cache.get_model(app_label, self.name) schema_editor.remove_field(model, model._meta.get_field_by_name(self.name)) model = app_cache.get_model(app_label, self.model_name) schema_editor.remove_field(model, model._meta.get_field_by_name(self.name)[0]) def database_backwards(self, app_label, schema_editor, from_state, to_state): app_cache = to_state.render() model = app_cache.get_model(app_label, self.name) schema_editor.add_field(model, model._meta.get_field_by_name(self.name)) model = app_cache.get_model(app_label, self.model_name) schema_editor.add_field(model, model._meta.get_field_by_name(self.name)[0])
tests/migrations/migrations/0002_second.py +1 −1 Original line number Diff line number Diff line Loading @@ -11,7 +11,7 @@ class Migration(migrations.Migration): migrations.RemoveField("Author", "silly_field"), migrations.AddField("Author", "important", models.BooleanField()), migrations.AddField("Author", "rating", models.IntegerField(default=0)), migrations.CreateModel( "Book", Loading
tests/migrations/test_executor.py 0 → 100644 +35 −0 Original line number Diff line number Diff line from django.test import TransactionTestCase from django.db import connection from django.db.migrations.executor import MigrationExecutor class ExecutorTests(TransactionTestCase): """ Tests the migration executor (full end-to-end running). Bear in mind that if these are failing you should fix the other test failures first, as they may be propagating into here. """ def test_run(self): """ Tests running a simple set of migrations. """ executor = MigrationExecutor(connection) # Let's look at the plan first and make sure it's up to scratch plan = executor.migration_plan([("migrations", "0002_second")]) self.assertEqual( plan, [ (executor.loader.graph.nodes["migrations", "0001_initial"], False), (executor.loader.graph.nodes["migrations", "0002_second"], False), ], ) # Were the tables there before? self.assertNotIn("migrations_author", connection.introspection.get_table_list(connection.cursor())) self.assertNotIn("migrations_book", connection.introspection.get_table_list(connection.cursor())) # Alright, let's try running it executor.migrate([("migrations", "0002_second")]) # Are the tables there now? self.assertIn("migrations_author", connection.introspection.get_table_list(connection.cursor())) self.assertIn("migrations_book", connection.introspection.get_table_list(connection.cursor()))
