from django.contrib.postgres.signals import (
get_citext_oids, get_hstore_oids, register_type_handlers,
)
from django.db import NotSupportedError, router
from django.db.migrations import AddIndex, RemoveIndex
from django.db.migrations.operations.base import Operation
[docs]class CreateExtension(Operation):
reversible = True
def __init__(self, name):
self.name = name
def state_forwards(self, app_label, state):
pass
def database_forwards(self, app_label, schema_editor, from_state, to_state):
if (
schema_editor.connection.vendor != 'postgresql' or
not router.allow_migrate(schema_editor.connection.alias, app_label)
):
return
if not self.extension_exists(schema_editor, self.name):
schema_editor.execute(
'CREATE EXTENSION IF NOT EXISTS %s' % schema_editor.quote_name(self.name)
)
# Clear cached, stale oids.
get_hstore_oids.cache_clear()
get_citext_oids.cache_clear()
# Registering new type handlers cannot be done before the extension is
# installed, otherwise a subsequent data migration would use the same
# connection.
register_type_handlers(schema_editor.connection)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
if not router.allow_migrate(schema_editor.connection.alias, app_label):
return
if self.extension_exists(schema_editor, self.name):
schema_editor.execute(
'DROP EXTENSION IF EXISTS %s' % schema_editor.quote_name(self.name)
)
# Clear cached, stale oids.
get_hstore_oids.cache_clear()
get_citext_oids.cache_clear()
def extension_exists(self, schema_editor, extension):
with schema_editor.connection.cursor() as cursor:
cursor.execute(
'SELECT 1 FROM pg_extension WHERE extname = %s',
[extension],
)
return bool(cursor.fetchone())
def describe(self):
return "Creates extension %s" % self.name
@property
def migration_name_fragment(self):
return 'create_extension_%s' % self.name
[docs]class BloomExtension(CreateExtension):
def __init__(self):
self.name = 'bloom'
[docs]class BtreeGinExtension(CreateExtension):
def __init__(self):
self.name = 'btree_gin'
[docs]class BtreeGistExtension(CreateExtension):
def __init__(self):
self.name = 'btree_gist'
[docs]class CITextExtension(CreateExtension):
def __init__(self):
self.name = 'citext'
[docs]class CryptoExtension(CreateExtension):
def __init__(self):
self.name = 'pgcrypto'
[docs]class HStoreExtension(CreateExtension):
def __init__(self):
self.name = 'hstore'
[docs]class TrigramExtension(CreateExtension):
def __init__(self):
self.name = 'pg_trgm'
[docs]class UnaccentExtension(CreateExtension):
def __init__(self):
self.name = 'unaccent'
class NotInTransactionMixin:
def _ensure_not_in_transaction(self, schema_editor):
if schema_editor.connection.in_atomic_block:
raise NotSupportedError(
'The %s operation cannot be executed inside a transaction '
'(set atomic = False on the migration).'
% self.__class__.__name__
)
[docs]class AddIndexConcurrently(NotInTransactionMixin, AddIndex):
"""Create an index using PostgreSQL's CREATE INDEX CONCURRENTLY syntax."""
atomic = False
def describe(self):
return 'Concurrently create index %s on field(s) %s of model %s' % (
self.index.name,
', '.join(self.index.fields),
self.model_name,
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
self._ensure_not_in_transaction(schema_editor)
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.add_index(model, self.index, concurrently=True)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
self._ensure_not_in_transaction(schema_editor)
model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.remove_index(model, self.index, concurrently=True)
[docs]class RemoveIndexConcurrently(NotInTransactionMixin, RemoveIndex):
"""Remove an index using PostgreSQL's DROP INDEX CONCURRENTLY syntax."""
atomic = False
def describe(self):
return 'Concurrently remove index %s from %s' % (self.name, self.model_name)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
self._ensure_not_in_transaction(schema_editor)
model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
from_model_state = from_state.models[app_label, self.model_name_lower]
index = from_model_state.get_index_by_name(self.name)
schema_editor.remove_index(model, index, concurrently=True)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
self._ensure_not_in_transaction(schema_editor)
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
to_model_state = to_state.models[app_label, self.model_name_lower]
index = to_model_state.get_index_by_name(self.name)
schema_editor.add_index(model, index, concurrently=True)
class CollationOperation(Operation):
def __init__(self, name, locale, *, provider='libc', deterministic=True):
self.name = name
self.locale = locale
self.provider = provider
self.deterministic = deterministic
def state_forwards(self, app_label, state):
pass
def deconstruct(self):
kwargs = {'name': self.name, 'locale': self.locale}
if self.provider and self.provider != 'libc':
kwargs['provider'] = self.provider
if self.deterministic is False:
kwargs['deterministic'] = self.deterministic
return (
self.__class__.__qualname__,
[],
kwargs,
)
def create_collation(self, schema_editor):
if (
self.deterministic is False and
not schema_editor.connection.features.supports_non_deterministic_collations
):
raise NotSupportedError(
'Non-deterministic collations require PostgreSQL 12+.'
)
if (
self.provider != 'libc' and
not schema_editor.connection.features.supports_alternate_collation_providers
):
raise NotSupportedError('Non-libc providers require PostgreSQL 10+.')
args = {'locale': schema_editor.quote_name(self.locale)}
if self.provider != 'libc':
args['provider'] = schema_editor.quote_name(self.provider)
if self.deterministic is False:
args['deterministic'] = 'false'
schema_editor.execute('CREATE COLLATION %(name)s (%(args)s)' % {
'name': schema_editor.quote_name(self.name),
'args': ', '.join(f'{option}={value}' for option, value in args.items()),
})
def remove_collation(self, schema_editor):
schema_editor.execute(
'DROP COLLATION %s' % schema_editor.quote_name(self.name),
)
[docs]class CreateCollation(CollationOperation):
"""Create a collation."""
def database_forwards(self, app_label, schema_editor, from_state, to_state):
if (
schema_editor.connection.vendor != 'postgresql' or
not router.allow_migrate(schema_editor.connection.alias, app_label)
):
return
self.create_collation(schema_editor)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
if not router.allow_migrate(schema_editor.connection.alias, app_label):
return
self.remove_collation(schema_editor)
def describe(self):
return f'Create collation {self.name}'
@property
def migration_name_fragment(self):
return 'create_collation_%s' % self.name.lower()
[docs]class RemoveCollation(CollationOperation):
"""Remove a collation."""
def database_forwards(self, app_label, schema_editor, from_state, to_state):
if (
schema_editor.connection.vendor != 'postgresql' or
not router.allow_migrate(schema_editor.connection.alias, app_label)
):
return
self.remove_collation(schema_editor)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
if not router.allow_migrate(schema_editor.connection.alias, app_label):
return
self.create_collation(schema_editor)
def describe(self):
return f'Remove collation {self.name}'
@property
def migration_name_fragment(self):
return 'remove_collation_%s' % self.name.lower()