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 = DatabaseValidation(self)
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
self.server_version = None
self.features = DatabaseFeatures(self)
self.ops = DatabaseOperations(self)
self.client = DatabaseClient(self)
self.creation = DatabaseCreation(self) #数据库创建器, from django.db.backends.mysql.creation import DatabaseCreation
self.introspection = DatabaseIntrospection(self)
self.validation = DatabaseValidation(self)
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 = DatabaseValidation(self)
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
self.server_version = None
self.features = DatabaseFeatures()
self.ops = mysqldb_base.DatabaseOperations()
self.client = DatabaseClient(self)
self.creation = DatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = DatabaseValidation(self)
self.pool = None
class DatabaseWrapper(BaseDatabaseWrapper):
vendor = 'mysql'
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',
}
Database = Database
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 = DatabaseValidation(self)
def get_connection_params(self):
kwargs = {
'conv': django_conversions,
'charset': 'utf8',
}
if not six.PY3:
kwargs['use_unicode'] = True
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'] = force_str(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
kwargs.update(settings_dict['OPTIONS'])
return kwargs
def get_new_connection(self, conn_params):
conn = Database.connect(**conn_params)
conn.encoders[SafeText] = conn.encoders[six.text_type]
conn.encoders[SafeBytes] = conn.encoders[bytes]
return conn
def init_connection_state(self):
cursor = self.connection.cursor()
# SQL_AUTO_IS_NULL in MySQL controls whether an AUTO_INCREMENT column
# on a recently-inserted row will return when the field is tested for
# NULL. Disabling this value brings this aspect of MySQL in line with
# SQL standards.
cursor.execute('SET SQL_AUTO_IS_NULL = 0')
cursor.close()
def create_cursor(self):
cursor = self.connection.cursor()
return CursorWrapper(cursor)
def _rollback(self):
try:
BaseDatabaseWrapper._rollback(self)
except Database.NotSupportedError:
pass
def _set_autocommit(self, autocommit):
self.connection.autocommit(autocommit)
def disable_constraint_checking(self):
"""
Disables foreign key checks, primarily for use in adding rows with forward references. Always returns True,
to indicate constraint checks need to be re-enabled.
"""
self.cursor().execute('SET foreign_key_checks=0')
return True
def enable_constraint_checking(self):
"""
Re-enable foreign key checks after they have been disabled.
"""
self.cursor().execute('SET foreign_key_checks=1')
def check_constraints(self, table_names=None):
"""
Checks 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.
Raises an IntegrityError on the first invalid foreign key reference encountered (if any) and provides
detailed information about the invalid reference in the error message.
Backends can override this method if they can more directly apply constraint checking (e.g. via "SET CONSTRAINTS
ALL IMMEDIATE")
"""
cursor = self.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 utils.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 DatabaseError:
return False
else:
return True
@cached_property
def mysql_version(self):
with self.temporary_connection():
server_info = self.connection.get_server_info()
match = server_version_re.match(server_info)
if not match:
raise Exception('Unable to determine MySQL version from version string %r' % server_info)
return tuple([int(x) for x in match.groups()])
class DatabaseWrapper(BaseDatabaseWrapper):
vendor = 'mysql'
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('%%', {})",
}
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 = DatabaseValidation(self)
def get_connection_params(self):
kwargs = {
'conv': django_conversions,
'charset': 'utf8',
}
if six.PY2:
kwargs['use_unicode'] = True
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'] = force_str(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
kwargs.update(settings_dict['OPTIONS'])
return kwargs
def get_new_connection(self, conn_params):
conn = Database.connect(**conn_params)
conn.encoders[SafeText] = conn.encoders[six.text_type]
conn.encoders[SafeBytes] = conn.encoders[bytes]
return conn
def init_connection_state(self):
with self.cursor() as cursor:
# SQL_AUTO_IS_NULL in MySQL controls whether an AUTO_INCREMENT column
# on a recently-inserted row will return when the field is tested for
# NULL. Disabling this value brings this aspect of MySQL in line with
# SQL standards.
cursor.execute('SET SQL_AUTO_IS_NULL = 0')
def create_cursor(self):
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):
"""
Disables foreign key checks, primarily for use in adding rows with forward references. Always returns True,
to indicate constraint checks need to be re-enabled.
"""
self.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:
self.cursor().execute('SET foreign_key_checks=1')
finally:
self.needs_rollback = needs_rollback
def check_constraints(self, table_names=None):
"""
Checks 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.
Raises an IntegrityError on the first invalid foreign key reference
encountered (if any) and provides detailed information about the
invalid reference in the error message.
Backends can override this method if they can more directly apply
constraint checking (e.g. via "SET CONSTRAINTS ALL IMMEDIATE")
"""
cursor = self.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 utils.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 mysql_version(self):
with self.temporary_connection():
server_info = self.connection.get_server_info()
match = server_version_re.match(server_info)
if not match:
raise Exception('Unable to determine MySQL version from version string %r' % server_info)
return tuple(int(x) for x in match.groups())
class DatabaseWrapper(BaseDatabaseWrapper):
vendor = 'mysql'
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',
}
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
self.server_version = None
self.features = DatabaseFeatures(self)
self.ops = DatabaseOperations(self)
self.client = DatabaseClient(self)
self.creation = DatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = DatabaseValidation(self)
def _valid_connection(self):
if self.connection is not None:
try:
self.connection.ping()
return True
except DatabaseError:
self.connection.close()
self.connection = None
return False
def _cursor(self):
new_connection = False
if not self._valid_connection():
new_connection = True
kwargs = {
'conv': django_conversions,
'charset': 'utf8',
'use_unicode': True,
}
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
kwargs.update(settings_dict['OPTIONS'])
self.connection = Database.connect(**kwargs)
self.connection.encoders[SafeUnicode] = self.connection.encoders[unicode]
self.connection.encoders[SafeString] = self.connection.encoders[str]
connection_created.send(sender=self.__class__, connection=self)
cursor = self.connection.cursor()
if new_connection:
# SQL_AUTO_IS_NULL in MySQL controls whether an AUTO_INCREMENT column
# on a recently-inserted row will return when the field is tested for
# NULL. Disabling this value brings this aspect of MySQL in line with
# SQL standards.
cursor.execute('SET SQL_AUTO_IS_NULL = 0')
return CursorWrapper(cursor)
def _rollback(self):
try:
BaseDatabaseWrapper._rollback(self)
except Database.NotSupportedError:
pass
def get_server_version(self):
if not self.server_version:
if not self._valid_connection():
self.cursor()
m = server_version_re.match(self.connection.get_server_info())
if not m:
raise Exception('Unable to determine MySQL version from version string %r' % self.connection.get_server_info())
self.server_version = tuple([int(x) for x in m.groups()])
return self.server_version
def disable_constraint_checking(self):
"""
Disables foreign key checks, primarily for use in adding rows with forward references. Always returns True,
to indicate constraint checks need to be re-enabled.
"""
self.cursor().execute('SET foreign_key_checks=0')
return True
def enable_constraint_checking(self):
"""
Re-enable foreign key checks after they have been disabled.
"""
self.cursor().execute('SET foreign_key_checks=1')
def check_constraints(self, table_names=None):
"""
Checks 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.
Raises an IntegrityError on the first invalid foreign key reference encountered (if any) and provides
detailed information about the invalid reference in the error message.
Backends can override this method if they can more directly apply constraint checking (e.g. via "SET CONSTRAINTS
ALL IMMEDIATE")
"""
cursor = self.cursor()
if table_names is None:
table_names = self.introspection.get_table_list(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 utils.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))
class DatabaseWrapper(BaseDatabaseWrapper):
vendor = "mysql"
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",
}
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
self.server_version = None
self.features = DatabaseFeatures(self)
self.ops = DatabaseOperations(self)
self.client = DatabaseClient(self)
self.creation = DatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = DatabaseValidation(self)
def _valid_connection(self):
if self.connection is not None:
try:
self.connection.ping()
return True
except DatabaseError:
self.connection.close()
self.connection = None
return False
def _cursor(self):
new_connection = False
if not self._valid_connection():
new_connection = True
kwargs = {"conv": django_conversions, "charset": "utf8", "use_unicode": True}
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"] = force_str(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
kwargs.update(settings_dict["OPTIONS"])
self.connection = Database.connect(**kwargs)
self.connection.encoders[SafeText] = self.connection.encoders[six.text_type]
self.connection.encoders[SafeBytes] = self.connection.encoders[bytes]
connection_created.send(sender=self.__class__, connection=self)
cursor = self.connection.cursor()
if new_connection:
# SQL_AUTO_IS_NULL in MySQL controls whether an AUTO_INCREMENT column
# on a recently-inserted row will return when the field is tested for
# NULL. Disabling this value brings this aspect of MySQL in line with
# SQL standards.
cursor.execute("SET SQL_AUTO_IS_NULL = 0")
return CursorWrapper(cursor)
def _rollback(self):
try:
BaseDatabaseWrapper._rollback(self)
except Database.NotSupportedError:
pass
@cached_property
def mysql_version(self):
if not self.server_version:
new_connection = False
if not self._valid_connection():
# Ensure we have a connection with the DB by using a temporary
# cursor
new_connection = True
self.cursor().close()
server_info = self.connection.get_server_info()
if new_connection:
# Make sure we close the connection
self.connection.close()
self.connection = None
m = server_version_re.match(server_info)
if not m:
raise Exception("Unable to determine MySQL version from version string %r" % server_info)
self.server_version = tuple([int(x) for x in m.groups()])
return self.server_version
def disable_constraint_checking(self):
"""
Disables foreign key checks, primarily for use in adding rows with forward references. Always returns True,
to indicate constraint checks need to be re-enabled.
"""
self.cursor().execute("SET foreign_key_checks=0")
return True
def enable_constraint_checking(self):
"""
Re-enable foreign key checks after they have been disabled.
"""
self.cursor().execute("SET foreign_key_checks=1")
def check_constraints(self, table_names=None):
"""
Checks 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.
Raises an IntegrityError on the first invalid foreign key reference encountered (if any) and provides
detailed information about the invalid reference in the error message.
Backends can override this method if they can more directly apply constraint checking (e.g. via "SET CONSTRAINTS
ALL IMMEDIATE")
"""
cursor = self.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 utils.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,
)
)
class DatabaseWrapper(BaseDatabaseWrapper):
vendor = 'mysql'
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',
}
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
self.server_version = None
self.features = DatabaseFeatures(self)
self.ops = DatabaseOperations(self)
self.client = DatabaseClient(self)
self.creation = DatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = DatabaseValidation(self)
def _valid_connection(self):
if self.connection is not None:
try:
self.connection.ping()
return True
except DatabaseError:
self.connection.close()
self.connection = None
return False
def _cursor(self):
if not self._valid_connection():
kwargs = {
'conv': django_conversions,
'charset': 'utf8',
'use_unicode': True,
}
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
kwargs.update(settings_dict['OPTIONS'])
self.connection = Database.connect(**kwargs)
self.connection.encoders[SafeUnicode] = self.connection.encoders[unicode]
self.connection.encoders[SafeString] = self.connection.encoders[str]
connection_created.send(sender=self.__class__, connection=self)
cursor = CursorWrapper(self.connection.cursor())
return cursor
def _rollback(self):
try:
BaseDatabaseWrapper._rollback(self)
except Database.NotSupportedError:
pass
def get_server_version(self):
if not self.server_version:
if not self._valid_connection():
self.cursor()
m = server_version_re.match(self.connection.get_server_info())
if not m:
raise Exception('Unable to determine MySQL version from version string %r' % self.connection.get_server_info())
self.server_version = tuple([int(x) for x in m.groups()])
return self.server_version
def disable_constraint_checking(self):
"""
Disables foreign key checks, primarily for use in adding rows with forward references. Always returns True,
to indicate constraint checks need to be re-enabled.
"""
self.cursor().execute('SET foreign_key_checks=0')
return True
def enable_constraint_checking(self):
"""
Re-enable foreign key checks after they have been disabled.
"""
self.cursor().execute('SET foreign_key_checks=1')
def check_constraints(self, table_names=None):
"""
Checks 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.
Raises an IntegrityError on the first invalid foreign key reference encountered (if any) and provides
detailed information about the invalid reference in the error message.
Backends can override this method if they can more directly apply constraint checking (e.g. via "SET CONSTRAINTS
ALL IMMEDIATE")
"""
cursor = self.cursor()
if table_names is None:
table_names = self.introspection.get_table_list(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 utils.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))
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',
'BinaryField': 'longblob',
'BooleanField': 'bool',
'CharField': 'varchar(%(max_length)s)',
'CommaSeparatedIntegerField': 'varchar(%(max_length)s)',
'DateField': 'date',
'DateTimeField': 'datetime',
'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)',
'NullBooleanField': 'bool',
'OneToOneField': 'integer',
'PositiveIntegerField': 'integer UNSIGNED',
'PositiveSmallIntegerField': 'smallint UNSIGNED',
'SlugField': 'varchar(%(max_length)s)',
'SmallIntegerField': 'smallint',
'TextField': 'longtext',
'TimeField': 'time',
'UUIDField': 'char(32)',
}
@cached_property
def data_types(self):
if self.features.supports_microsecond_precision:
return dict(self._data_types, DateTimeField='datetime(6)', TimeField='time(6)')
else:
return self._data_types
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('%%', {})",
}
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 = DatabaseValidation(self)
def get_connection_params(self):
kwargs = {
'conv': django_conversions,
'charset': 'utf8',
}
if six.PY2:
kwargs['use_unicode'] = True
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'] = force_str(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
kwargs.update(settings_dict['OPTIONS'])
return kwargs
def get_new_connection(self, conn_params):
conn = Database.connect(**conn_params)
conn.encoders[SafeText] = conn.encoders[six.text_type]
conn.encoders[SafeBytes] = conn.encoders[bytes]
return conn
def init_connection_state(self):
with self.cursor() as cursor:
# SQL_AUTO_IS_NULL in MySQL controls whether an AUTO_INCREMENT column
# on a recently-inserted row will return when the field is tested for
# NULL. Disabling this value brings this aspect of MySQL in line with
# SQL standards.
cursor.execute('SET SQL_AUTO_IS_NULL = 0')
def create_cursor(self):
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):
"""
Disables foreign key checks, primarily for use in adding rows with forward references. Always returns True,
to indicate constraint checks need to be re-enabled.
"""
self.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:
self.cursor().execute('SET foreign_key_checks=1')
finally:
self.needs_rollback = needs_rollback
def check_constraints(self, table_names=None):
"""
Checks 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.
Raises an IntegrityError on the first invalid foreign key reference
encountered (if any) and provides detailed information about the
invalid reference in the error message.
Backends can override this method if they can more directly apply
constraint checking (e.g. via "SET CONSTRAINTS ALL IMMEDIATE")
"""
cursor = self.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 utils.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 mysql_version(self):
with self.temporary_connection():
server_info = self.connection.get_server_info()
match = server_version_re.match(server_info)
if not match:
raise Exception('Unable to determine MySQL version from version string %r' % server_info)
return tuple(int(x) for x in match.groups())
class DatabaseWrapper(BaseDatabaseWrapper):
vendor = 'mysql'
# 操作
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',
}
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
self.server_version = None
self.features = DatabaseFeatures(self)
self.ops = DatabaseOperations(self)
self.client = DatabaseClient(self)
self.creation = DatabaseCreation(self) #数据库创建器, from django.db.backends.mysql.creation import DatabaseCreation
self.introspection = DatabaseIntrospection(self)
self.validation = DatabaseValidation(self)
def _valid_connection(self):
if self.connection is not None:
try:
self.connection.ping()
return True
except DatabaseError:
self.connection.close()
self.connection = None
return False
def _cursor(self):
new_connection = False
if not self._valid_connection():
new_connection = True
kwargs = {
'conv': django_conversions,
'charset': 'utf8',
'use_unicode': True,
}
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'] = force_str(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
kwargs.update(settings_dict['OPTIONS'])
# 此处设置 connection, 已经有 MySQL 内部实现
self.connection = Database.connect(**kwargs)
self.connection.encoders[SafeText] = self.connection.encoders[six.text_type]
self.connection.encoders[SafeBytes] = self.connection.encoders[bytes]
connection_created.send(sender=self.__class__, connection=self)
cursor = self.connection.cursor() 获取游标
if new_connection:
"""
另外还可以用"WHERE auto_col IS NULL"条件选择出新插入的行，即在INSERT后马上用:
SELECT * FROM t WHERE a IS NULL;
选 择出来的将是新插入的行，而非真正的满足"a IS NULL"条件的行。但你要是再执行一次上述查询，则返回的又变成了真正的满足"a IS NULL"条件的行，由于a是主键，因此肯定会返回空集。这看上去很诡异是吗，不过MySQL也不想这么干，但ODBC标准里曾有这种用法，为了支持 ODBC，MySQL也是没办法啊。不过可以将SQL_AUTO_IS_NULL设为0来禁止这一用法。
"""
# SQL_AUTO_IS_NULL in MySQL controls whether an AUTO_INCREMENT column
# on a recently-inserted row will return when the field is tested for
# NULL. Disabling this value brings this aspect of MySQL in line with
# SQL standards.
cursor.execute('SET SQL_AUTO_IS_NULL = 0')
return CursorWrapper(cursor)
def _rollback(self):
try:
BaseDatabaseWrapper._rollback(self)
except Database.NotSupportedError:
pass
@cached_property
def mysql_version(self):
if not self.server_version:
new_connection = False
if not self._valid_connection():
# Ensure we have a connection with the DB by using a temporary
# cursor
new_connection = True
self.cursor().close()
server_info = self.connection.get_server_info()
if new_connection:
# Make sure we close the connection
self.connection.close()
self.connection = None
m = server_version_re.match(server_info)
if not m:
raise Exception('Unable to determine MySQL version from version string %r' % server_info)
self.server_version = tuple([int(x) for x in m.groups()])
return self.server_version
关闭外键约束
def disable_constraint_checking(self):
"""
Disables foreign key checks, primarily for use in adding rows with forward references. Always returns True,
to indicate constraint checks need to be re-enabled.
MySQL还原数据库，禁用和启用外键约束的方法(FOREIGN_KEY_CHECKS)
有时还原数据库时，因为表有约束导致40014错误，可以通过关闭外键约束，还原成功时再启用.
禁用
SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0
启用
SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS
"""
self.cursor().execute('SET foreign_key_checks=0')
return True
def enable_constraint_checking(self):
"""
Re-enable foreign key checks after they have been disabled.
"""
self.cursor().execute('SET foreign_key_checks=1')
def check_constraints(self, table_names=None):
"""
用在 disable_constraint_checking 和 enable_constraint_checking 之间, 为的是看是否在外键约束关闭期间是否有不合法的数据进入.
Checks each table name in `table_names` for rows with invalid foreign key references. This method is
intended to be used in conjunction with 连接 `disable_constraint_checking()` and `enable_constraint_checking()`, to
determine if rows with invalid references were entered while constraint checks were off.
Raises an IntegrityError on the first invalid foreign key reference encountered (if any) and provides
detailed information about the invalid reference in the error message.
Backends can override this method if they can more directly apply constraint checking (e.g. via "SET CONSTRAINTS
ALL IMMEDIATE")
"""
cursor = self.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: 没有主键
continue
key_columns = self.introspection.get_key_columns(cursor, table_name)
for column_name, referenced_table_name, referenced_column_name in key_columns:
# 检测外键不丢失
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))
# 出现错误, 需要报错. 一般是外键丢失, 或者主键无效
for bad_row in cursor.fetchall():
raise utils.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))
