488 lines
18 KiB
Python
488 lines
18 KiB
Python
"""
|
|
PostgreSQL database backend for Django.
|
|
|
|
Requires psycopg2 >= 2.8.4 or psycopg >= 3.1.8
|
|
"""
|
|
|
|
import asyncio
|
|
import threading
|
|
import warnings
|
|
from contextlib import contextmanager
|
|
|
|
from django.conf import settings
|
|
from django.core.exceptions import ImproperlyConfigured
|
|
from django.db import DatabaseError as WrappedDatabaseError
|
|
from django.db import connections
|
|
from django.db.backends.base.base import BaseDatabaseWrapper
|
|
from django.db.backends.utils import CursorDebugWrapper as BaseCursorDebugWrapper
|
|
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:
|
|
try:
|
|
import psycopg as Database
|
|
except ImportError:
|
|
import psycopg2 as Database
|
|
except ImportError:
|
|
raise ImproperlyConfigured("Error loading psycopg2 or psycopg module")
|
|
|
|
|
|
def psycopg_version():
|
|
version = Database.__version__.split(" ", 1)[0]
|
|
return get_version_tuple(version)
|
|
|
|
|
|
if psycopg_version() < (2, 8, 4):
|
|
raise ImproperlyConfigured(
|
|
f"psycopg2 version 2.8.4 or newer is required; you have {Database.__version__}"
|
|
)
|
|
if (3,) <= psycopg_version() < (3, 1, 8):
|
|
raise ImproperlyConfigured(
|
|
f"psycopg version 3.1.8 or newer is required; you have {Database.__version__}"
|
|
)
|
|
|
|
|
|
from .psycopg_any import IsolationLevel, is_psycopg3 # NOQA isort:skip
|
|
|
|
if is_psycopg3:
|
|
from psycopg import adapters, sql
|
|
from psycopg.pq import Format
|
|
|
|
from .psycopg_any import get_adapters_template, register_tzloader
|
|
|
|
TIMESTAMPTZ_OID = adapters.types["timestamptz"].oid
|
|
|
|
else:
|
|
import psycopg2.extensions
|
|
import psycopg2.extras
|
|
|
|
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)
|
|
|
|
# Some of these import psycopg, 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
|
|
|
|
|
|
def _get_varchar_column(data):
|
|
if data["max_length"] is None:
|
|
return "varchar"
|
|
return "varchar(%(max_length)s)" % data
|
|
|
|
|
|
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": "integer",
|
|
"BigAutoField": "bigint",
|
|
"BinaryField": "bytea",
|
|
"BooleanField": "boolean",
|
|
"CharField": _get_varchar_column,
|
|
"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",
|
|
"JSONField": "jsonb",
|
|
"OneToOneField": "integer",
|
|
"PositiveBigIntegerField": "bigint",
|
|
"PositiveIntegerField": "integer",
|
|
"PositiveSmallIntegerField": "smallint",
|
|
"SlugField": "varchar(%(max_length)s)",
|
|
"SmallAutoField": "smallint",
|
|
"SmallIntegerField": "smallint",
|
|
"TextField": "text",
|
|
"TimeField": "time",
|
|
"UUIDField": "uuid",
|
|
}
|
|
data_type_check_constraints = {
|
|
"PositiveBigIntegerField": '"%(column)s" >= 0',
|
|
"PositiveIntegerField": '"%(column)s" >= 0',
|
|
"PositiveSmallIntegerField": '"%(column)s" >= 0',
|
|
}
|
|
data_types_suffix = {
|
|
"AutoField": "GENERATED BY DEFAULT AS IDENTITY",
|
|
"BigAutoField": "GENERATED BY DEFAULT AS IDENTITY",
|
|
"SmallAutoField": "GENERATED BY DEFAULT AS IDENTITY",
|
|
}
|
|
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_database_version(self):
|
|
"""
|
|
Return a tuple of the database's version.
|
|
E.g. for pg_version 120004, return (12, 4).
|
|
"""
|
|
return divmod(self.pg_version, 10000)
|
|
|
|
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"] == "" and not settings_dict.get("OPTIONS", {}).get(
|
|
"service"
|
|
):
|
|
raise ImproperlyConfigured(
|
|
"settings.DATABASES is improperly configured. "
|
|
"Please supply the NAME or OPTIONS['service'] 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(),
|
|
)
|
|
)
|
|
if settings_dict["NAME"]:
|
|
conn_params = {
|
|
"dbname": settings_dict["NAME"],
|
|
**settings_dict["OPTIONS"],
|
|
}
|
|
elif settings_dict["NAME"] is None:
|
|
# Connect to the default 'postgres' db.
|
|
settings_dict.get("OPTIONS", {}).pop("service", None)
|
|
conn_params = {"dbname": "postgres", **settings_dict["OPTIONS"]}
|
|
else:
|
|
conn_params = {**settings_dict["OPTIONS"]}
|
|
conn_params["client_encoding"] = "UTF8"
|
|
|
|
conn_params.pop("assume_role", None)
|
|
conn_params.pop("isolation_level", None)
|
|
server_side_binding = conn_params.pop("server_side_binding", None)
|
|
conn_params.setdefault(
|
|
"cursor_factory",
|
|
ServerBindingCursor
|
|
if is_psycopg3 and server_side_binding is True
|
|
else Cursor,
|
|
)
|
|
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"]
|
|
if is_psycopg3:
|
|
conn_params["context"] = get_adapters_template(
|
|
settings.USE_TZ, self.timezone
|
|
)
|
|
# Disable prepared statements by default to keep connection poolers
|
|
# working. Can be reenabled via OPTIONS in the settings dict.
|
|
conn_params["prepare_threshold"] = conn_params.pop(
|
|
"prepare_threshold", None
|
|
)
|
|
return conn_params
|
|
|
|
@async_unsafe
|
|
def get_new_connection(self, 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"]
|
|
set_isolation_level = False
|
|
try:
|
|
isolation_level_value = options["isolation_level"]
|
|
except KeyError:
|
|
self.isolation_level = IsolationLevel.READ_COMMITTED
|
|
else:
|
|
# Set the isolation level to the value from OPTIONS.
|
|
try:
|
|
self.isolation_level = IsolationLevel(isolation_level_value)
|
|
set_isolation_level = True
|
|
except ValueError:
|
|
raise ImproperlyConfigured(
|
|
f"Invalid transaction isolation level {isolation_level_value} "
|
|
f"specified. Use one of the psycopg.IsolationLevel values."
|
|
)
|
|
connection = self.Database.connect(**conn_params)
|
|
if set_isolation_level:
|
|
connection.isolation_level = self.isolation_level
|
|
if not is_psycopg3:
|
|
# Register dummy loads() to avoid a round trip from psycopg2's
|
|
# decode to json.dumps() to json.loads(), when using a custom
|
|
# decoder in JSONField.
|
|
psycopg2.extras.register_default_jsonb(
|
|
conn_or_curs=connection, loads=lambda x: x
|
|
)
|
|
return connection
|
|
|
|
def ensure_timezone(self):
|
|
if self.connection is None:
|
|
return False
|
|
conn_timezone_name = self.connection.info.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 ensure_role(self):
|
|
if self.connection is None:
|
|
return False
|
|
if new_role := self.settings_dict.get("OPTIONS", {}).get("assume_role"):
|
|
with self.connection.cursor() as cursor:
|
|
sql = self.ops.compose_sql("SET ROLE %s", [new_role])
|
|
cursor.execute(sql)
|
|
return True
|
|
return False
|
|
|
|
def init_connection_state(self):
|
|
super().init_connection_state()
|
|
|
|
# Commit after setting the time zone.
|
|
commit_tz = self.ensure_timezone()
|
|
# Set the role on the connection. This is useful if the credential used
|
|
# to login is not the same as the role that owns database resources. As
|
|
# can be the case when using temporary or ephemeral credentials.
|
|
commit_role = self.ensure_role()
|
|
|
|
if (commit_role or commit_tz) and 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()
|
|
|
|
if is_psycopg3:
|
|
# Register the cursor timezone only if the connection disagrees, to
|
|
# avoid copying the adapter map.
|
|
tzloader = self.connection.adapters.get_loader(TIMESTAMPTZ_OID, Format.TEXT)
|
|
if self.timezone != tzloader.timezone:
|
|
register_tzloader(self.timezone, cursor)
|
|
else:
|
|
cursor.tzinfo_factory = self.tzinfo_factory if settings.USE_TZ else None
|
|
return cursor
|
|
|
|
def tzinfo_factory(self, offset):
|
|
return self.timezone
|
|
|
|
@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:
|
|
current_task = asyncio.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.
|
|
"""
|
|
with self.cursor() as cursor:
|
|
cursor.execute("SET CONSTRAINTS ALL IMMEDIATE")
|
|
cursor.execute("SET CONSTRAINTS ALL DEFERRED")
|
|
|
|
def is_usable(self):
|
|
try:
|
|
# Use a psycopg cursor directly, bypassing Django's utilities.
|
|
with self.connection.cursor() as cursor:
|
|
cursor.execute("SELECT 1")
|
|
except Database.Error:
|
|
return False
|
|
else:
|
|
return True
|
|
|
|
@contextmanager
|
|
def _nodb_cursor(self):
|
|
cursor = None
|
|
try:
|
|
with super()._nodb_cursor() as cursor:
|
|
yield cursor
|
|
except (Database.DatabaseError, WrappedDatabaseError):
|
|
if cursor is not None:
|
|
raise
|
|
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"
|
|
):
|
|
conn = self.__class__(
|
|
{
|
|
**self.settings_dict,
|
|
"NAME": connection.settings_dict["NAME"],
|
|
},
|
|
alias=self.alias,
|
|
)
|
|
try:
|
|
with conn.cursor() as cursor:
|
|
yield cursor
|
|
finally:
|
|
conn.close()
|
|
break
|
|
else:
|
|
raise
|
|
|
|
@cached_property
|
|
def pg_version(self):
|
|
with self.temporary_connection():
|
|
return self.connection.info.server_version
|
|
|
|
def make_debug_cursor(self, cursor):
|
|
return CursorDebugWrapper(cursor, self)
|
|
|
|
|
|
if is_psycopg3:
|
|
|
|
class CursorMixin:
|
|
"""
|
|
A subclass of psycopg cursor implementing callproc.
|
|
"""
|
|
|
|
def callproc(self, name, args=None):
|
|
if not isinstance(name, sql.Identifier):
|
|
name = sql.Identifier(name)
|
|
|
|
qparts = [sql.SQL("SELECT * FROM "), name, sql.SQL("(")]
|
|
if args:
|
|
for item in args:
|
|
qparts.append(sql.Literal(item))
|
|
qparts.append(sql.SQL(","))
|
|
del qparts[-1]
|
|
|
|
qparts.append(sql.SQL(")"))
|
|
stmt = sql.Composed(qparts)
|
|
self.execute(stmt)
|
|
return args
|
|
|
|
class ServerBindingCursor(CursorMixin, Database.Cursor):
|
|
pass
|
|
|
|
class Cursor(CursorMixin, Database.ClientCursor):
|
|
pass
|
|
|
|
class CursorDebugWrapper(BaseCursorDebugWrapper):
|
|
def copy(self, statement):
|
|
with self.debug_sql(statement):
|
|
return self.cursor.copy(statement)
|
|
|
|
else:
|
|
Cursor = psycopg2.extensions.cursor
|
|
|
|
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)
|