# Copyright (c) 2020, 2021, Oracle and/or its affiliates.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License, version 2.0, as
# published by the Free Software Foundation.
#
# This program is also distributed with certain software (including
# but not limited to OpenSSL) that is licensed under separate terms,
# as designated in a particular file or component or in included license
# documentation. The authors of MySQL hereby grant you an
# additional permission to link the program and your derivative works
# with the separately licensed software that they have included with
# MySQL.
#
# Without limiting anything contained in the foregoing, this file,
# which is part of MySQL Connector/Python, is also subject to the
# Universal FOSS Exception, version 1.0, a copy of which can be found at
# http://oss.oracle.com/licenses/universal-foss-exception.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the GNU General Public License, version 2.0, for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
"""Django database Backend using MySQL Connector/Python.
This Django database backend is heavily based on the MySQL backend from Django.
Changes include:
* Support for microseconds (MySQL 5.6.3 and later)
* Using INFORMATION_SCHEMA where possible
* Using new defaults for, for example SQL_AUTO_IS_NULL
Requires and comes with MySQL Connector/Python v8.0.22 and later:
http://dev.mysql.com/downloads/connector/python/
"""
import warnings
import sys
from datetime import datetime
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.db import IntegrityError
from django.db.backends.base.base import BaseDatabaseWrapper
from django.db import utils
from django.utils.functional import cached_property
from django.utils import dateparse, timezone
try:
import mysql.connector
from mysql.connector.conversion import MySQLConverter
except ImportError as err:
raise ImproperlyConfigured(
"Error loading mysql.connector module: {0}".format(err))
try:
from _mysql_connector import datetime_to_mysql, time_to_mysql
except ImportError:
HAVE_CEXT = False
else:
HAVE_CEXT = True
from .client import DatabaseClient
from .creation import DatabaseCreation
from .introspection import DatabaseIntrospection
from .validation import DatabaseValidation
from .features import DatabaseFeatures
from .operations import DatabaseOperations
from .schema import DatabaseSchemaEditor
Error = mysql.connector.Error
DatabaseError = mysql.connector.DatabaseError
NotSupportedError = mysql.connector.NotSupportedError
OperationalError = mysql.connector.OperationalError
ProgrammingError = mysql.connector.ProgrammingError
def adapt_datetime_with_timezone_support(value):
# Equivalent to DateTimeField.get_db_prep_value. Used only by raw SQL.
if settings.USE_TZ:
if timezone.is_naive(value):
warnings.warn("MySQL received a naive datetime (%s)"
" while time zone support is active." % value,
RuntimeWarning)
default_timezone = timezone.get_default_timezone()
value = timezone.make_aware(value, default_timezone)
value = value.astimezone(timezone.utc).replace(tzinfo=None)
if HAVE_CEXT:
return datetime_to_mysql(value)
else:
return value.strftime("%Y-%m-%d %H:%M:%S.%f")
class CursorWrapper:
"""Wrapper around MySQL Connector/Python's cursor class.
The cursor class is defined by the options passed to MySQL
Connector/Python. If buffered option is True in those options,
MySQLCursorBuffered will be used.
"""
codes_for_integrityerror = (
1048, # Column cannot be null
1690, # BIGINT UNSIGNED value is out of range
3819, # CHECK constraint is violated
4025, # CHECK constraint failed
)
def __init__(self, cursor):
self.cursor = cursor
def _adapt_execute_args_dict(self, args):
if not args:
return args
new_args = dict(args)
for key, value in args.items():
if isinstance(value, datetime):
new_args[key] = adapt_datetime_with_timezone_support(value)
return new_args
def _adapt_execute_args(self, args):
if not args:
return args
new_args = list(args)
for i, arg in enumerate(args):
if isinstance(arg, datetime):
new_args[i] = adapt_datetime_with_timezone_support(arg)
return tuple(new_args)
def execute(self, query, args=None):
"""Executes the given operation
This wrapper method around the execute()-method of the cursor is
mainly needed to re-raise using different exceptions.
"""
if isinstance(args, dict):
new_args = self._adapt_execute_args_dict(args)
else:
new_args = self._adapt_execute_args(args)
try:
return self.cursor.execute(query, new_args)
except mysql.connector.OperationalError as e:
if e.args[0] in self.codes_for_integrityerror:
raise IntegrityError(*tuple(e.args))
raise
def executemany(self, query, args):
"""Executes the given operation
This wrapper method around the executemany()-method of the cursor is
mainly needed to re-raise using different exceptions.
"""
try:
return self.cursor.executemany(query, args)
except mysql.connector.OperationalError as e:
if e.args[0] in self.codes_for_integrityerror:
raise IntegrityError(*tuple(e.args))
raise
def __getattr__(self, attr):
"""Return attribute of wrapped cursor"""
return getattr(self.cursor, attr)
def __iter__(self):
"""Returns iterator over wrapped cursor"""
return iter(self.cursor)
class DatabaseWrapper(BaseDatabaseWrapper):
vendor = 'mysql'
# This dictionary maps Field objects to their associated MySQL 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 AUTO_INCREMENT',
'BigAutoField': 'bigint AUTO_INCREMENT',
'BinaryField': 'longblob',
'BooleanField': 'bool',
'CharField': 'varchar(%(max_length)s)',
'DateField': 'date',
'DateTimeField': 'datetime(6)',
'DecimalField': 'numeric(%(max_digits)s, %(decimal_places)s)',
'DurationField': 'bigint',
'FileField': 'varchar(%(max_length)s)',
'FilePathField': 'varchar(%(max_length)s)',
'FloatField': 'double precision',
'IntegerField': 'integer',
'BigIntegerField': 'bigint',
'IPAddressField': 'char(15)',
'GenericIPAddressField': 'char(39)',
'JSONField': 'json',
'NullBooleanField': 'bool',
'OneToOneField': 'integer',
'PositiveBigIntegerField': 'bigint UNSIGNED',
'PositiveIntegerField': 'integer UNSIGNED',
'PositiveSmallIntegerField': 'smallint UNSIGNED',
'SlugField': 'varchar(%(max_length)s)',
'SmallAutoField': 'smallint AUTO_INCREMENT',
'SmallIntegerField': 'smallint',
'TextField': 'longtext',
'TimeField': 'time(6)',
'UUIDField': 'char(32)',
}
# For these data types:
# - MySQL < 8.0.13 doesn't accept default values and
# implicitly treat them as nullable
# - all versions of MySQL doesn't support full width database
# indexes
_limited_data_types = (
'tinyblob', 'blob', 'mediumblob', 'longblob', 'tinytext', 'text',
'mediumtext', 'longtext', 'json',
)
operators = {
'exact': '= %s',
'iexact': 'LIKE %s',
'contains': 'LIKE BINARY %s',
'icontains': 'LIKE %s',
'regex': 'REGEXP BINARY %s',
'iregex': 'REGEXP %s',
'gt': '> %s',
'gte': '>= %s',
'lt': '< %s',
'lte': '<= %s',
'startswith': 'LIKE BINARY %s',
'endswith': 'LIKE BINARY %s',
'istartswith': 'LIKE %s',
'iendswith': 'LIKE %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 BINARY CONCAT('%%', {}, '%%')",
'icontains': "LIKE CONCAT('%%', {}, '%%')",
'startswith': "LIKE BINARY CONCAT({}, '%%')",
'istartswith': "LIKE CONCAT({}, '%%')",
'endswith': "LIKE BINARY CONCAT('%%', {})",
'iendswith': "LIKE CONCAT('%%', {})",
}
isolation_levels = {
'read uncommitted',
'read committed',
'repeatable read',
'serializable',
}
Database = mysql.connector
SchemaEditorClass = DatabaseSchemaEditor
# Classes instantiated in __init__().
client_class = DatabaseClient
creation_class = DatabaseCreation
features_class = DatabaseFeatures
introspection_class = DatabaseIntrospection
ops_class = DatabaseOperations
validation_class = DatabaseValidation
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
options = self.settings_dict.get('OPTIONS')
if options:
self._use_pure = options.get('use_pure', not HAVE_CEXT)
converter_class = options.get(
'converter_class',
DjangoMySQLConverter,
)
if not issubclass(converter_class, DjangoMySQLConverter):
raise ProgrammingError(
'Converter class should be a subclass of '
'mysql.connector.django.base.DjangoMySQLConverter'
)
self.converter = converter_class()
else:
self.converter = DjangoMySQLConverter()
self._use_pure = not HAVE_CEXT
def __getattr__(self, attr):
if attr.startswith("mysql_is"):
return False
raise AttributeError
def get_connection_params(self):
kwargs = {
'charset': 'utf8',
'use_unicode': True,
'buffered': False,
'consume_results': True,
}
settings_dict = self.settings_dict
if settings_dict['USER']:
kwargs['user'] = settings_dict['USER']
if settings_dict['NAME']:
kwargs['database'] = settings_dict['NAME']
if settings_dict['PASSWORD']:
kwargs['passwd'] = settings_dict['PASSWORD']
if settings_dict['HOST'].startswith('/'):
kwargs['unix_socket'] = settings_dict['HOST']
elif settings_dict['HOST']:
kwargs['host'] = settings_dict['HOST']
if settings_dict['PORT']:
kwargs['port'] = int(settings_dict['PORT'])
# Raise exceptions for database warnings if DEBUG is on
kwargs['raise_on_warnings'] = settings.DEBUG
kwargs['client_flags'] = [
# Need potentially affected rows on UPDATE
mysql.connector.constants.ClientFlag.FOUND_ROWS,
]
try:
kwargs.update(settings_dict['OPTIONS'])
except KeyError:
# OPTIONS missing is OK
pass
return kwargs
def get_new_connection(self, conn_params):
if not 'converter_class' in conn_params:
conn_params['converter_class'] = DjangoMySQLConverter
cnx = mysql.connector.connect(**conn_params)
return cnx
def init_connection_state(self):
assignments = []
if self.features.is_sql_auto_is_null_enabled:
# SQL_AUTO_IS_NULL controls whether an AUTO_INCREMENT column on
# a recently inserted row will return when the field is tested
# for NULL. Disabling this brings this aspect of MySQL in line
# with SQL standards.
assignments.append('SET SQL_AUTO_IS_NULL = 0')
if assignments:
with self.cursor() as cursor:
cursor.execute('; '.join(assignments))
if 'AUTOCOMMIT' in self.settings_dict:
try:
self.set_autocommit(self.settings_dict['AUTOCOMMIT'])
except AttributeError:
self._set_autocommit(self.settings_dict['AUTOCOMMIT'])
def create_cursor(self, name=None):
cursor = self.connection.cursor()
return CursorWrapper(cursor)
def _rollback(self):
try:
BaseDatabaseWrapper._rollback(self)
except NotSupportedError:
pass
def _set_autocommit(self, autocommit):
with self.wrap_database_errors:
self.connection.autocommit = autocommit
def disable_constraint_checking(self):
"""
Disable foreign key checks, primarily for use in adding rows with
forward references. Always return True to indicate constraint checks
need to be re-enabled.
"""
with self.cursor() as cursor:
cursor.execute('SET foreign_key_checks=0')
return True
def enable_constraint_checking(self):
"""
Re-enable foreign key checks after they have been disabled.
"""
# Override needs_rollback in case constraint_checks_disabled is
# nested inside transaction.atomic.
self.needs_rollback, needs_rollback = False, self.needs_rollback
try:
with self.cursor() as cursor:
cursor.execute('SET foreign_key_checks=1')
finally:
self.needs_rollback = needs_rollback
def check_constraints(self, table_names=None):
"""
Check each table name in `table_names` for rows with invalid foreign
key references. This method is intended to be used in conjunction with
`disable_constraint_checking()` and `enable_constraint_checking()`, to
determine if rows with invalid references were entered while constraint
checks were off.
"""
with self.cursor() as cursor:
if table_names is None:
table_names = self.introspection.table_names(cursor)
for table_name in table_names:
primary_key_column_name = self.introspection.get_primary_key_column(cursor, table_name)
if not primary_key_column_name:
continue
key_columns = self.introspection.get_key_columns(cursor, table_name)
for column_name, referenced_table_name, referenced_column_name in key_columns:
cursor.execute(
"""
SELECT REFERRING.`%s`, REFERRING.`%s` FROM `%s` as REFERRING
LEFT JOIN `%s` as REFERRED
ON (REFERRING.`%s` = REFERRED.`%s`)
WHERE REFERRING.`%s` IS NOT NULL AND REFERRED.`%s` IS NULL
""" % (
primary_key_column_name, column_name, table_name,
referenced_table_name, column_name, referenced_column_name,
column_name, referenced_column_name,
)
)
for bad_row in cursor.fetchall():
raise IntegrityError(
"The row in table '%s' with primary key '%s' has an invalid "
"foreign key: %s.%s contains a value '%s' that does not "
"have a corresponding value in %s.%s."
% (
table_name, bad_row[0], table_name, column_name,
bad_row[1], referenced_table_name, referenced_column_name,
)
)
def is_usable(self):
try:
self.connection.ping()
except Error:
return False
else:
return True
@cached_property
def display_name(self):
return 'MySQL'
@cached_property
def data_type_check_constraints(self):
if self.features.supports_column_check_constraints:
check_constraints = {
'PositiveBigIntegerField': '`%(column)s` >= 0',
'PositiveIntegerField': '`%(column)s` >= 0',
'PositiveSmallIntegerField': '`%(column)s` >= 0',
}
return check_constraints
return {}
@cached_property
def mysql_server_data(self):
with self.temporary_connection() as cursor:
# Select some server variables and test if the time zone
# definitions are installed. CONVERT_TZ returns NULL if 'UTC'
# timezone isn't loaded into the mysql.time_zone table.
cursor.execute("""
SELECT VERSION(),
@@sql_mode,
@@default_storage_engine,
@@sql_auto_is_null,
@@lower_case_table_names,
CONVERT_TZ('2001-01-01 01:00:00', 'UTC', 'UTC') IS NOT NULL
""")
row = cursor.fetchone()
return {
'version': row[0],
'sql_mode': row[1],
'default_storage_engine': row[2],
'sql_auto_is_null': bool(row[3]),
'lower_case_table_names': bool(row[4]),
'has_zoneinfo_database': bool(row[5]),
}
@cached_property
def mysql_server_info(self):
with self.temporary_connection() as cursor:
cursor.execute('SELECT VERSION()')
return cursor.fetchone()[0]
@cached_property
def mysql_version(self):
config = self.get_connection_params()
with mysql.connector.connect(**config) as conn:
server_version = conn.get_server_version()
return server_version
@cached_property
def sql_mode(self):
with self.cursor() as cursor:
cursor.execute('SELECT @@sql_mode')
sql_mode = cursor.fetchone()
return set(sql_mode[0].split(',') if sql_mode else ())
@property
def use_pure(self):
return self._use_pure
class DjangoMySQLConverter(MySQLConverter):
"""Custom converter for Django."""
def _TIME_to_python(self, value, dsc=None):
"""Return MySQL TIME data type as datetime.time()
Returns datetime.time()
"""
return dateparse.parse_time(value.decode('utf-8'))
def __DATETIME_to_python(self, value, dsc=None):
"""Connector/Python always returns naive datetime.datetime
Connector/Python always returns naive timestamps since MySQL has
no time zone support. Since Django needs non-naive, we need to add
the UTC time zone.
Returns datetime.datetime()
"""
if not value:
return None
dt = MySQLConverter._DATETIME_to_python(self, value)
if dt is None:
return None
if settings.USE_TZ and timezone.is_naive(dt):
dt = dt.replace(tzinfo=timezone.utc)
return dt
def _safestring_to_mysql(self, value):
return self._str_to_mysql(value)
def _safetext_to_mysql(self, value):
return self._str_to_mysql(value)
def _safebytes_to_mysql(self, value):
return self._bytes_to_mysql(value)