327 lines
12 KiB
Python
327 lines
12 KiB
Python
"""
|
|
PostgreSQL database backend for Django.
|
|
|
|
Requires psycopg 2: http://initd.org/projects/psycopg2
|
|
"""
|
|
|
|
import asyncio
|
|
import threading
|
|
import warnings
|
|
|
|
from django.conf import settings
|
|
from django.core.exceptions import ImproperlyConfigured
|
|
from django.db import connections
|
|
from django.db.backends.base.base import BaseDatabaseWrapper
|
|
from django.db.backends.utils import (
|
|
CursorDebugWrapper as BaseCursorDebugWrapper,
|
|
)
|
|
from django.db.utils import DatabaseError as WrappedDatabaseError
|
|
from django.utils.asyncio import async_unsafe
|
|
from django.utils.functional import cached_property
|
|
from django.utils.safestring import SafeString
|
|
from django.utils.version import get_version_tuple
|
|
|
|
try:
|
|
import psycopg2 as Database
|
|
import psycopg2.extensions
|
|
import psycopg2.extras
|
|
except ImportError as e:
|
|
raise ImproperlyConfigured("Error loading psycopg2 module: %s" % e)
|
|
|
|
|
|
def psycopg2_version():
|
|
version = psycopg2.__version__.split(' ', 1)[0]
|
|
return get_version_tuple(version)
|
|
|
|
|
|
PSYCOPG2_VERSION = psycopg2_version()
|
|
|
|
if PSYCOPG2_VERSION < (2, 5, 4):
|
|
raise ImproperlyConfigured("psycopg2_version 2.5.4 or newer is required; you have %s" % psycopg2.__version__)
|
|
|
|
|
|
# Some of these import psycopg2, so import them after checking if it's installed.
|
|
from .client import DatabaseClient # NOQA isort:skip
|
|
from .creation import DatabaseCreation # NOQA isort:skip
|
|
from .features import DatabaseFeatures # NOQA isort:skip
|
|
from .introspection import DatabaseIntrospection # NOQA isort:skip
|
|
from .operations import DatabaseOperations # NOQA isort:skip
|
|
from .schema import DatabaseSchemaEditor # NOQA isort:skip
|
|
from .utils import utc_tzinfo_factory # NOQA isort:skip
|
|
|
|
psycopg2.extensions.register_adapter(SafeString, psycopg2.extensions.QuotedString)
|
|
psycopg2.extras.register_uuid()
|
|
|
|
# Register support for inet[] manually so we don't have to handle the Inet()
|
|
# object on load all the time.
|
|
INETARRAY_OID = 1041
|
|
INETARRAY = psycopg2.extensions.new_array_type(
|
|
(INETARRAY_OID,),
|
|
'INETARRAY',
|
|
psycopg2.extensions.UNICODE,
|
|
)
|
|
psycopg2.extensions.register_type(INETARRAY)
|
|
|
|
|
|
class DatabaseWrapper(BaseDatabaseWrapper):
|
|
vendor = 'postgresql'
|
|
display_name = 'PostgreSQL'
|
|
# This dictionary maps Field objects to their associated PostgreSQL column
|
|
# types, as strings. Column-type strings can contain format strings; they'll
|
|
# be interpolated against the values of Field.__dict__ before being output.
|
|
# If a column type is set to None, it won't be included in the output.
|
|
data_types = {
|
|
'AutoField': 'serial',
|
|
'BigAutoField': 'bigserial',
|
|
'BinaryField': 'bytea',
|
|
'BooleanField': 'boolean',
|
|
'CharField': 'varchar(%(max_length)s)',
|
|
'DateField': 'date',
|
|
'DateTimeField': 'timestamp with time zone',
|
|
'DecimalField': 'numeric(%(max_digits)s, %(decimal_places)s)',
|
|
'DurationField': 'interval',
|
|
'FileField': 'varchar(%(max_length)s)',
|
|
'FilePathField': 'varchar(%(max_length)s)',
|
|
'FloatField': 'double precision',
|
|
'IntegerField': 'integer',
|
|
'BigIntegerField': 'bigint',
|
|
'IPAddressField': 'inet',
|
|
'GenericIPAddressField': 'inet',
|
|
'NullBooleanField': 'boolean',
|
|
'OneToOneField': 'integer',
|
|
'PositiveIntegerField': 'integer',
|
|
'PositiveSmallIntegerField': 'smallint',
|
|
'SlugField': 'varchar(%(max_length)s)',
|
|
'SmallAutoField': 'smallserial',
|
|
'SmallIntegerField': 'smallint',
|
|
'TextField': 'text',
|
|
'TimeField': 'time',
|
|
'UUIDField': 'uuid',
|
|
}
|
|
data_type_check_constraints = {
|
|
'PositiveIntegerField': '"%(column)s" >= 0',
|
|
'PositiveSmallIntegerField': '"%(column)s" >= 0',
|
|
}
|
|
operators = {
|
|
'exact': '= %s',
|
|
'iexact': '= UPPER(%s)',
|
|
'contains': 'LIKE %s',
|
|
'icontains': 'LIKE UPPER(%s)',
|
|
'regex': '~ %s',
|
|
'iregex': '~* %s',
|
|
'gt': '> %s',
|
|
'gte': '>= %s',
|
|
'lt': '< %s',
|
|
'lte': '<= %s',
|
|
'startswith': 'LIKE %s',
|
|
'endswith': 'LIKE %s',
|
|
'istartswith': 'LIKE UPPER(%s)',
|
|
'iendswith': 'LIKE UPPER(%s)',
|
|
}
|
|
|
|
# The patterns below are used to generate SQL pattern lookup clauses when
|
|
# the right-hand side of the lookup isn't a raw string (it might be an expression
|
|
# or the result of a bilateral transformation).
|
|
# In those cases, special characters for LIKE operators (e.g. \, *, _) should be
|
|
# escaped on database side.
|
|
#
|
|
# Note: we use str.format() here for readability as '%' is used as a wildcard for
|
|
# the LIKE operator.
|
|
pattern_esc = r"REPLACE(REPLACE(REPLACE({}, E'\\', E'\\\\'), E'%%', E'\\%%'), E'_', E'\\_')"
|
|
pattern_ops = {
|
|
'contains': "LIKE '%%' || {} || '%%'",
|
|
'icontains': "LIKE '%%' || UPPER({}) || '%%'",
|
|
'startswith': "LIKE {} || '%%'",
|
|
'istartswith': "LIKE UPPER({}) || '%%'",
|
|
'endswith': "LIKE '%%' || {}",
|
|
'iendswith': "LIKE '%%' || UPPER({})",
|
|
}
|
|
|
|
Database = Database
|
|
SchemaEditorClass = DatabaseSchemaEditor
|
|
# Classes instantiated in __init__().
|
|
client_class = DatabaseClient
|
|
creation_class = DatabaseCreation
|
|
features_class = DatabaseFeatures
|
|
introspection_class = DatabaseIntrospection
|
|
ops_class = DatabaseOperations
|
|
# PostgreSQL backend-specific attributes.
|
|
_named_cursor_idx = 0
|
|
|
|
def get_connection_params(self):
|
|
settings_dict = self.settings_dict
|
|
# None may be used to connect to the default 'postgres' db
|
|
if settings_dict['NAME'] == '':
|
|
raise ImproperlyConfigured(
|
|
"settings.DATABASES is improperly configured. "
|
|
"Please supply the NAME value.")
|
|
if len(settings_dict['NAME'] or '') > self.ops.max_name_length():
|
|
raise ImproperlyConfigured(
|
|
"The database name '%s' (%d characters) is longer than "
|
|
"PostgreSQL's limit of %d characters. Supply a shorter NAME "
|
|
"in settings.DATABASES." % (
|
|
settings_dict['NAME'],
|
|
len(settings_dict['NAME']),
|
|
self.ops.max_name_length(),
|
|
)
|
|
)
|
|
conn_params = {
|
|
'database': settings_dict['NAME'] or 'postgres',
|
|
**settings_dict['OPTIONS'],
|
|
}
|
|
conn_params.pop('isolation_level', None)
|
|
if settings_dict['USER']:
|
|
conn_params['user'] = settings_dict['USER']
|
|
if settings_dict['PASSWORD']:
|
|
conn_params['password'] = settings_dict['PASSWORD']
|
|
if settings_dict['HOST']:
|
|
conn_params['host'] = settings_dict['HOST']
|
|
if settings_dict['PORT']:
|
|
conn_params['port'] = settings_dict['PORT']
|
|
return conn_params
|
|
|
|
@async_unsafe
|
|
def get_new_connection(self, conn_params):
|
|
connection = Database.connect(**conn_params)
|
|
|
|
# self.isolation_level must be set:
|
|
# - after connecting to the database in order to obtain the database's
|
|
# default when no value is explicitly specified in options.
|
|
# - before calling _set_autocommit() because if autocommit is on, that
|
|
# will set connection.isolation_level to ISOLATION_LEVEL_AUTOCOMMIT.
|
|
options = self.settings_dict['OPTIONS']
|
|
try:
|
|
self.isolation_level = options['isolation_level']
|
|
except KeyError:
|
|
self.isolation_level = connection.isolation_level
|
|
else:
|
|
# Set the isolation level to the value from OPTIONS.
|
|
if self.isolation_level != connection.isolation_level:
|
|
connection.set_session(isolation_level=self.isolation_level)
|
|
|
|
return connection
|
|
|
|
def ensure_timezone(self):
|
|
if self.connection is None:
|
|
return False
|
|
conn_timezone_name = self.connection.get_parameter_status('TimeZone')
|
|
timezone_name = self.timezone_name
|
|
if timezone_name and conn_timezone_name != timezone_name:
|
|
with self.connection.cursor() as cursor:
|
|
cursor.execute(self.ops.set_time_zone_sql(), [timezone_name])
|
|
return True
|
|
return False
|
|
|
|
def init_connection_state(self):
|
|
self.connection.set_client_encoding('UTF8')
|
|
|
|
timezone_changed = self.ensure_timezone()
|
|
if timezone_changed:
|
|
# Commit after setting the time zone (see #17062)
|
|
if not self.get_autocommit():
|
|
self.connection.commit()
|
|
|
|
@async_unsafe
|
|
def create_cursor(self, name=None):
|
|
if name:
|
|
# In autocommit mode, the cursor will be used outside of a
|
|
# transaction, hence use a holdable cursor.
|
|
cursor = self.connection.cursor(name, scrollable=False, withhold=self.connection.autocommit)
|
|
else:
|
|
cursor = self.connection.cursor()
|
|
cursor.tzinfo_factory = utc_tzinfo_factory if settings.USE_TZ else None
|
|
return cursor
|
|
|
|
@async_unsafe
|
|
def chunked_cursor(self):
|
|
self._named_cursor_idx += 1
|
|
# Get the current async task
|
|
# Note that right now this is behind @async_unsafe, so this is
|
|
# unreachable, but in future we'll start loosening this restriction.
|
|
# For now, it's here so that every use of "threading" is
|
|
# also async-compatible.
|
|
try:
|
|
if hasattr(asyncio, 'current_task'):
|
|
# Python 3.7 and up
|
|
current_task = asyncio.current_task()
|
|
else:
|
|
# Python 3.6
|
|
current_task = asyncio.Task.current_task()
|
|
except RuntimeError:
|
|
current_task = None
|
|
# Current task can be none even if the current_task call didn't error
|
|
if current_task:
|
|
task_ident = str(id(current_task))
|
|
else:
|
|
task_ident = 'sync'
|
|
# Use that and the thread ident to get a unique name
|
|
return self._cursor(
|
|
name='_django_curs_%d_%s_%d' % (
|
|
# Avoid reusing name in other threads / tasks
|
|
threading.current_thread().ident,
|
|
task_ident,
|
|
self._named_cursor_idx,
|
|
)
|
|
)
|
|
|
|
def _set_autocommit(self, autocommit):
|
|
with self.wrap_database_errors:
|
|
self.connection.autocommit = autocommit
|
|
|
|
def check_constraints(self, table_names=None):
|
|
"""
|
|
Check constraints by setting them to immediate. Return them to deferred
|
|
afterward.
|
|
"""
|
|
self.cursor().execute('SET CONSTRAINTS ALL IMMEDIATE')
|
|
self.cursor().execute('SET CONSTRAINTS ALL DEFERRED')
|
|
|
|
def is_usable(self):
|
|
try:
|
|
# Use a psycopg cursor directly, bypassing Django's utilities.
|
|
self.connection.cursor().execute("SELECT 1")
|
|
except Database.Error:
|
|
return False
|
|
else:
|
|
return True
|
|
|
|
@property
|
|
def _nodb_connection(self):
|
|
nodb_connection = super()._nodb_connection
|
|
try:
|
|
nodb_connection.ensure_connection()
|
|
except (Database.DatabaseError, WrappedDatabaseError):
|
|
warnings.warn(
|
|
"Normally Django will use a connection to the 'postgres' database "
|
|
"to avoid running initialization queries against the production "
|
|
"database when it's not needed (for example, when running tests). "
|
|
"Django was unable to create a connection to the 'postgres' database "
|
|
"and will use the first PostgreSQL database instead.",
|
|
RuntimeWarning
|
|
)
|
|
for connection in connections.all():
|
|
if connection.vendor == 'postgresql' and connection.settings_dict['NAME'] != 'postgres':
|
|
return self.__class__(
|
|
{**self.settings_dict, 'NAME': connection.settings_dict['NAME']},
|
|
alias=self.alias,
|
|
)
|
|
return nodb_connection
|
|
|
|
@cached_property
|
|
def pg_version(self):
|
|
with self.temporary_connection():
|
|
return self.connection.server_version
|
|
|
|
def make_debug_cursor(self, cursor):
|
|
return CursorDebugWrapper(cursor, self)
|
|
|
|
|
|
class CursorDebugWrapper(BaseCursorDebugWrapper):
|
|
def copy_expert(self, sql, file, *args):
|
|
with self.debug_sql(sql):
|
|
return self.cursor.copy_expert(sql, file, *args)
|
|
|
|
def copy_to(self, file, table, *args, **kwargs):
|
|
with self.debug_sql(sql='COPY %s TO STDOUT' % table):
|
|
return self.cursor.copy_to(file, table, *args, **kwargs)
|