forked from s442783/HighNeed_projekt_inz
380 lines
15 KiB
Python
380 lines
15 KiB
Python
|
"""
|
||
|
|
MySQL database backend for Django.
|
||
|
|
|
||
|
|
Requires mysqlclient: https://pypi.org/project/mysqlclient/
|
||
|
|
"""
|
||
|
|
from django.core.exceptions import ImproperlyConfigured
|
||
|
|
from django.db import IntegrityError
|
||
|
|
from django.db.backends import utils as backend_utils
|
||
|
|
from django.db.backends.base.base import BaseDatabaseWrapper
|
||
|
|
from django.utils.asyncio import async_unsafe
|
||
|
|
from django.utils.functional import cached_property
|
||
|
|
from django.utils.regex_helper import _lazy_re_compile
|
||
|
|
|
||
|
|
try:
|
||
|
|
import MySQLdb as Database
|
||
|
|
except ImportError as err:
|
||
|
|
raise ImproperlyConfigured(
|
||
|
|
'Error loading MySQLdb module.\n'
|
||
|
|
'Did you install mysqlclient?'
|
||
|
|
) from err
|
||
|
|
|
||
|
|
from MySQLdb.constants import CLIENT, FIELD_TYPE # isort:skip
|
||
|
|
from MySQLdb.converters import conversions # isort:skip
|
||
|
|
|
||
|
|
# Some of these import MySQLdb, 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 .validation import DatabaseValidation # isort:skip
|
||
|
|
|
||
|
|
version = Database.version_info
|
||
|
|
if version < (1, 4, 0):
|
||
|
|
raise ImproperlyConfigured('mysqlclient 1.4.0 or newer is required; you have %s.' % Database.__version__)
|
||
|
|
|
||
|
|
|
||
|
|
# MySQLdb returns TIME columns as timedelta -- they are more like timedelta in
|
||
|
|
# terms of actual behavior as they are signed and include days -- and Django
|
||
|
|
# expects time.
|
||
|
|
django_conversions = {
|
||
|
|
**conversions,
|
||
|
|
**{FIELD_TYPE.TIME: backend_utils.typecast_time},
|
||
|
|
}
|
||
|
|
|
||
|
|
# This should match the numerical portion of the version numbers (we can treat
|
||
|
|
# versions like 5.0.24 and 5.0.24a as the same).
|
||
|
|
server_version_re = _lazy_re_compile(r'(\d{1,2})\.(\d{1,2})\.(\d{1,2})')
|
||
|
|
|
||
|
|
|
||
|
|
class CursorWrapper:
|
||
|
|
"""
|
||
|
|
A thin wrapper around MySQLdb's normal cursor class that catches particular
|
||
|
|
exception instances and reraises them with the correct types.
|
||
|
|
|
||
|
|
Implemented as a wrapper, rather than a subclass, so that it isn't stuck
|
||
|
|
to the particular underlying representation returned by Connection.cursor().
|
||
|
|
"""
|
||
|
|
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 execute(self, query, args=None):
|
||
|
|
try:
|
||
|
|
# args is None means no string interpolation
|
||
|
|
return self.cursor.execute(query, args)
|
||
|
|
except Database.OperationalError as e:
|
||
|
|
# Map some error codes to IntegrityError, since they seem to be
|
||
|
|
# misclassified and Django would prefer the more logical place.
|
||
|
|
if e.args[0] in self.codes_for_integrityerror:
|
||
|
|
raise IntegrityError(*tuple(e.args))
|
||
|
|
raise
|
||
|
|
|
||
|
|
def executemany(self, query, args):
|
||
|
|
try:
|
||
|
|
return self.cursor.executemany(query, args)
|
||
|
|
except Database.OperationalError as e:
|
||
|
|
# Map some error codes to IntegrityError, since they seem to be
|
||
|
|
# misclassified and Django would prefer the more logical place.
|
||
|
|
if e.args[0] in self.codes_for_integrityerror:
|
||
|
|
raise IntegrityError(*tuple(e.args))
|
||
|
|
raise
|
||
|
|
|
||
|
|
def __getattr__(self, attr):
|
||
|
|
return getattr(self.cursor, attr)
|
||
|
|
|
||
|
|
def __iter__(self):
|
||
|
|
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 and MariaDB < 10.2.1 don't accept default values and
|
||
|
|
# implicitly treat them as nullable
|
||
|
|
# - all versions of MySQL and MariaDB don'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',
|
||
|
|
'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 = Database
|
||
|
|
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 get_connection_params(self):
|
||
|
|
kwargs = {
|
||
|
|
'conv': django_conversions,
|
||
|
|
'charset': 'utf8',
|
||
|
|
}
|
||
|
|
settings_dict = self.settings_dict
|
||
|
|
if settings_dict['USER']:
|
||
|
|
kwargs['user'] = settings_dict['USER']
|
||
|
|
if settings_dict['NAME']:
|
||
|
|
kwargs['db'] = 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'])
|
||
|
|
# We need the number of potentially affected rows after an
|
||
|
|
# "UPDATE", not the number of changed rows.
|
||
|
|
kwargs['client_flag'] = CLIENT.FOUND_ROWS
|
||
|
|
# Validate the transaction isolation level, if specified.
|
||
|
|
options = settings_dict['OPTIONS'].copy()
|
||
|
|
isolation_level = options.pop('isolation_level', 'read committed')
|
||
|
|
if isolation_level:
|
||
|
|
isolation_level = isolation_level.lower()
|
||
|
|
if isolation_level not in self.isolation_levels:
|
||
|
|
raise ImproperlyConfigured(
|
||
|
|
"Invalid transaction isolation level '%s' specified.\n"
|
||
|
|
"Use one of %s, or None." % (
|
||
|
|
isolation_level,
|
||
|
|
', '.join("'%s'" % s for s in sorted(self.isolation_levels))
|
||
|
|
))
|
||
|
|
self.isolation_level = isolation_level
|
||
|
|
kwargs.update(options)
|
||
|
|
return kwargs
|
||
|
|
|
||
|
|
@async_unsafe
|
||
|
|
def get_new_connection(self, conn_params):
|
||
|
|
return Database.connect(**conn_params)
|
||
|
|
|
||
|
|
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 self.isolation_level:
|
||
|
|
assignments.append('SET SESSION TRANSACTION ISOLATION LEVEL %s' % self.isolation_level.upper())
|
||
|
|
|
||
|
|
if assignments:
|
||
|
|
with self.cursor() as cursor:
|
||
|
|
cursor.execute('; '.join(assignments))
|
||
|
|
|
||
|
|
@async_unsafe
|
||
|
|
def create_cursor(self, name=None):
|
||
|
|
cursor = self.connection.cursor()
|
||
|
|
return CursorWrapper(cursor)
|
||
|
|
|
||
|
|
def _rollback(self):
|
||
|
|
try:
|
||
|
|
BaseDatabaseWrapper._rollback(self)
|
||
|
|
except Database.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 Database.Error:
|
||
|
|
return False
|
||
|
|
else:
|
||
|
|
return True
|
||
|
|
|
||
|
|
@cached_property
|
||
|
|
def display_name(self):
|
||
|
|
return 'MariaDB' if self.mysql_is_mariadb else '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',
|
||
|
|
}
|
||
|
|
if self.mysql_is_mariadb and self.mysql_version < (10, 4, 3):
|
||
|
|
# MariaDB < 10.4.3 doesn't automatically use the JSON_VALID as
|
||
|
|
# a check constraint.
|
||
|
|
check_constraints['JSONField'] = 'JSON_VALID(`%(column)s`)'
|
||
|
|
return check_constraints
|
||
|
|
return {}
|
||
|
|
|
||
|
|
@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):
|
||
|
|
match = server_version_re.match(self.mysql_server_info)
|
||
|
|
if not match:
|
||
|
|
raise Exception('Unable to determine MySQL version from version string %r' % self.mysql_server_info)
|
||
|
|
return tuple(int(x) for x in match.groups())
|
||
|
|
|
||
|
|
@cached_property
|
||
|
|
def mysql_is_mariadb(self):
|
||
|
|
return 'mariadb' in self.mysql_server_info.lower()
|
||
|
|
|
||
|
|
@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 ())
|