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 AddConstraint, AddIndex, RemoveIndex
from django.db.migrations.operations.base import Operation
from django.db.models.constraints import CheckConstraint
[документация]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)
if hasattr(schema_editor.connection, "register_geometry_adapters"):
schema_editor.connection.register_geometry_adapters(
schema_editor.connection.connection, True
)
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
[документация]class BloomExtension(CreateExtension):
def __init__(self):
self.name = "bloom"
[документация]class BtreeGinExtension(CreateExtension):
def __init__(self):
self.name = "btree_gin"
[документация]class BtreeGistExtension(CreateExtension):
def __init__(self):
self.name = "btree_gist"
[документация]class CITextExtension(CreateExtension):
def __init__(self):
self.name = "citext"
[документация]class CryptoExtension(CreateExtension):
def __init__(self):
self.name = "pgcrypto"
[документация]class HStoreExtension(CreateExtension):
def __init__(self):
self.name = "hstore"
[документация]class TrigramExtension(CreateExtension):
def __init__(self):
self.name = "pg_trgm"
[документация]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__
)
[документация]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)
[документация]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):
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),
)
[документация]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()
[документация]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()
[документация]class AddConstraintNotValid(AddConstraint):
"""
Add a table constraint without enforcing validation, using PostgreSQL's
NOT VALID syntax.
"""
def __init__(self, model_name, constraint):
if not isinstance(constraint, CheckConstraint):
raise TypeError(
"AddConstraintNotValid.constraint must be a check constraint."
)
super().__init__(model_name, constraint)
def describe(self):
return "Create not valid constraint %s on model %s" % (
self.constraint.name,
self.model_name,
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
constraint_sql = self.constraint.create_sql(model, schema_editor)
if constraint_sql:
# Constraint.create_sql returns interpolated SQL which makes
# params=None a necessity to avoid escaping attempts on
# execution.
schema_editor.execute(str(constraint_sql) + " NOT VALID", params=None)
@property
def migration_name_fragment(self):
return super().migration_name_fragment + "_not_valid"
[документация]class ValidateConstraint(Operation):
"""Validate a table NOT VALID constraint."""
def __init__(self, model_name, name):
self.model_name = model_name
self.name = name
def describe(self):
return "Validate constraint %s on model %s" % (self.name, self.model_name)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.execute(
"ALTER TABLE %s VALIDATE CONSTRAINT %s"
% (
schema_editor.quote_name(model._meta.db_table),
schema_editor.quote_name(self.name),
)
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
# PostgreSQL does not provide a way to make a constraint invalid.
pass
def state_forwards(self, app_label, state):
pass
@property
def migration_name_fragment(self):
return "%s_validate_%s" % (self.model_name.lower(), self.name.lower())
def deconstruct(self):
return (
self.__class__.__name__,
[],
{
"model_name": self.model_name,
"name": self.name,
},
)