Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
241 lines (209 sloc) 9.35 kb
"""
PostgreSQL database backend for Django.
Requires psycopg 2: http://initd.org/projects/psycopg2
"""
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.db.backends.base.base import BaseDatabaseWrapper
from django.db.backends.base.validation import BaseDatabaseValidation
from django.utils.encoding import force_str
from django.utils.functional import cached_property
from django.utils.safestring import SafeBytes, SafeText
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 tuple(int(v) for v in version.split('.') if v.isdigit())
PSYCOPG2_VERSION = psycopg2_version()
if PSYCOPG2_VERSION < (2, 4, 5):
raise ImproperlyConfigured("psycopg2_version 2.4.5 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 # isort:skip
from .creation import DatabaseCreation # isort:skip
from .features import DatabaseFeatures # isort:skip
from .introspection import DatabaseIntrospection # isort:skip
from .operations import DatabaseOperations # isort:skip
from .schema import DatabaseSchemaEditor # isort:skip
from .utils import utc_tzinfo_factory # isort:skip
from .version import get_version # isort:skip
DatabaseError = Database.DatabaseError
IntegrityError = Database.IntegrityError
psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
psycopg2.extensions.register_type(psycopg2.extensions.UNICODEARRAY)
psycopg2.extensions.register_adapter(SafeBytes, psycopg2.extensions.QuotedString)
psycopg2.extensions.register_adapter(SafeText, 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'
# 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',
'BinaryField': 'bytea',
'BooleanField': 'boolean',
'CharField': 'varchar(%(max_length)s)',
'CommaSeparatedIntegerField': '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)',
'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({}, '\', '\\'), '%%', '\%%'), '_', '\_')"
pattern_ops = {
'contains': "LIKE '%%' || {} || '%%'",
'icontains': "LIKE '%%' || UPPER({}) || '%%'",
'startswith': "LIKE {} || '%%'",
'istartswith': "LIKE UPPER({}) || '%%'",
'endswith': "LIKE '%%' || {}",
'iendswith': "LIKE '%%' || UPPER({})",
}
Database = Database
SchemaEditorClass = DatabaseSchemaEditor
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
self.features = DatabaseFeatures(self)
self.ops = DatabaseOperations(self)
self.client = DatabaseClient(self)
self.creation = DatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = BaseDatabaseValidation(self)
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'] == '':
from django.core.exceptions import ImproperlyConfigured
raise ImproperlyConfigured(
"settings.DATABASES is improperly configured. "
"Please supply the NAME value.")
conn_params = {
'database': settings_dict['NAME'] or 'postgres',
}
conn_params.update(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'] = force_str(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
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 init_connection_state(self):
self.connection.set_client_encoding('UTF8')
tz = self.settings_dict['TIME_ZONE']
conn_tz = self.connection.get_parameter_status('TimeZone')
if conn_tz != tz:
cursor = self.connection.cursor()
try:
cursor.execute(self.ops.set_time_zone_sql(), [tz])
finally:
cursor.close()
# Commit after setting the time zone (see #17062)
if not self.get_autocommit():
self.connection.commit()
def create_cursor(self):
cursor = self.connection.cursor()
cursor.tzinfo_factory = utc_tzinfo_factory if settings.USE_TZ else None
return cursor
def _set_autocommit(self, autocommit):
with self.wrap_database_errors:
self.connection.autocommit = autocommit
def check_constraints(self, table_names=None):
"""
To check constraints, we set constraints to immediate. Then, when, we're done we must ensure they
are returned to deferred.
"""
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
@cached_property
def psycopg2_version(self):
return PSYCOPG2_VERSION
@cached_property
def pg_version(self):
with self.temporary_connection():
return get_version(self.connection)
Jump to Line
Something went wrong with that request. Please try again.