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author | ttt | 2017-05-13 00:29:47 +0530 |
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committer | ttt | 2017-05-13 00:29:47 +0530 |
commit | abf599be33b383a6a5baf9493093b2126a622ac8 (patch) | |
tree | 4c5ab6e0d935d5e65fabcf0258e4a00dd20a5afa /lib/python2.7/site-packages/django/db/backends/mysql/base.py | |
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added all server files
Diffstat (limited to 'lib/python2.7/site-packages/django/db/backends/mysql/base.py')
-rw-r--r-- | lib/python2.7/site-packages/django/db/backends/mysql/base.py | 533 |
1 files changed, 533 insertions, 0 deletions
diff --git a/lib/python2.7/site-packages/django/db/backends/mysql/base.py b/lib/python2.7/site-packages/django/db/backends/mysql/base.py new file mode 100644 index 0000000..ea04a5e --- /dev/null +++ b/lib/python2.7/site-packages/django/db/backends/mysql/base.py @@ -0,0 +1,533 @@ +""" +MySQL database backend for Django. + +Requires MySQLdb: http://sourceforge.net/projects/mysql-python +""" +from __future__ import unicode_literals + +import datetime +import re +import sys +import warnings + +try: + import MySQLdb as Database +except ImportError as e: + from django.core.exceptions import ImproperlyConfigured + raise ImproperlyConfigured("Error loading MySQLdb module: %s" % e) + +from django.utils.functional import cached_property + +# We want version (1, 2, 1, 'final', 2) or later. We can't just use +# lexicographic ordering in this check because then (1, 2, 1, 'gamma') +# inadvertently passes the version test. +version = Database.version_info +if (version < (1, 2, 1) or (version[:3] == (1, 2, 1) and + (len(version) < 5 or version[3] != 'final' or version[4] < 2))): + from django.core.exceptions import ImproperlyConfigured + raise ImproperlyConfigured("MySQLdb-1.2.1p2 or newer is required; you have %s" % Database.__version__) + +from MySQLdb.converters import conversions, Thing2Literal +from MySQLdb.constants import FIELD_TYPE, CLIENT + +try: + import pytz +except ImportError: + pytz = None + +from django.conf import settings +from django.db import utils +from django.db.backends import * +from django.db.backends.mysql.client import DatabaseClient +from django.db.backends.mysql.creation import DatabaseCreation +from django.db.backends.mysql.introspection import DatabaseIntrospection +from django.db.backends.mysql.validation import DatabaseValidation +from django.utils.encoding import force_str, force_text +from django.utils.safestring import SafeBytes, SafeText +from django.utils import six +from django.utils import timezone + +# Raise exceptions for database warnings if DEBUG is on +if settings.DEBUG: + warnings.filterwarnings("error", category=Database.Warning) + +DatabaseError = Database.DatabaseError +IntegrityError = Database.IntegrityError + +# It's impossible to import datetime_or_None directly from MySQLdb.times +parse_datetime = conversions[FIELD_TYPE.DATETIME] + +def parse_datetime_with_timezone_support(value): + dt = parse_datetime(value) + # Confirm that dt is naive before overwriting its tzinfo. + if dt is not None and settings.USE_TZ and timezone.is_naive(dt): + dt = dt.replace(tzinfo=timezone.utc) + return dt + +def adapt_datetime_with_timezone_support(value, conv): + # 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) + return Thing2Literal(value.strftime("%Y-%m-%d %H:%M:%S"), conv) + +# MySQLdb-1.2.1 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, so we still need to override that. We also need to +# add special handling for SafeText and SafeBytes as MySQLdb's type +# checking is too tight to catch those (see Django ticket #6052). +# Finally, MySQLdb always returns naive datetime objects. However, when +# timezone support is active, Django expects timezone-aware datetime objects. +django_conversions = conversions.copy() +django_conversions.update({ + FIELD_TYPE.TIME: util.typecast_time, + FIELD_TYPE.DECIMAL: util.typecast_decimal, + FIELD_TYPE.NEWDECIMAL: util.typecast_decimal, + FIELD_TYPE.DATETIME: parse_datetime_with_timezone_support, + datetime.datetime: adapt_datetime_with_timezone_support, +}) + +# 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). Based on the list of version +# at http://dev.mysql.com/doc/refman/4.1/en/news.html and +# http://dev.mysql.com/doc/refman/5.0/en/news.html . +server_version_re = re.compile(r'(\d{1,2})\.(\d{1,2})\.(\d{1,2})') + +# MySQLdb-1.2.1 and newer automatically makes use of SHOW WARNINGS on +# MySQL-4.1 and newer, so the MysqlDebugWrapper is unnecessary. Since the +# point is to raise Warnings as exceptions, this can be done with the Python +# warning module, and this is setup when the connection is created, and the +# standard util.CursorDebugWrapper can be used. Also, using sql_mode +# TRADITIONAL will automatically cause most warnings to be treated as errors. + +class CursorWrapper(object): + """ + A thin wrapper around MySQLdb's normal cursor class so that we can catch + particular exception instances and reraise them with the right types. + + Implemented as a wrapper, rather than a subclass, so that we aren't stuck + to the particular underlying representation returned by Connection.cursor(). + """ + codes_for_integrityerror = (1048,) + + 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: + six.reraise(utils.IntegrityError, utils.IntegrityError(*tuple(e.args)), sys.exc_info()[2]) + 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: + six.reraise(utils.IntegrityError, utils.IntegrityError(*tuple(e.args)), sys.exc_info()[2]) + raise + + def __getattr__(self, attr): + if attr in self.__dict__: + return self.__dict__[attr] + else: + return getattr(self.cursor, attr) + + def __iter__(self): + return iter(self.cursor) + +class DatabaseFeatures(BaseDatabaseFeatures): + empty_fetchmany_value = () + update_can_self_select = False + allows_group_by_pk = True + related_fields_match_type = True + allow_sliced_subqueries = False + has_bulk_insert = True + has_select_for_update = True + has_select_for_update_nowait = False + supports_forward_references = False + supports_long_model_names = False + supports_microsecond_precision = False + supports_regex_backreferencing = False + supports_date_lookup_using_string = False + supports_timezones = False + requires_explicit_null_ordering_when_grouping = True + allows_primary_key_0 = False + uses_savepoints = True + atomic_transactions = False + + def __init__(self, connection): + super(DatabaseFeatures, self).__init__(connection) + + @cached_property + def _mysql_storage_engine(self): + "Internal method used in Django tests. Don't rely on this from your code" + cursor = self.connection.cursor() + cursor.execute('CREATE TABLE INTROSPECT_TEST (X INT)') + # This command is MySQL specific; the second column + # will tell you the default table type of the created + # table. Since all Django's test tables will have the same + # table type, that's enough to evaluate the feature. + cursor.execute("SHOW TABLE STATUS WHERE Name='INTROSPECT_TEST'") + result = cursor.fetchone() + cursor.execute('DROP TABLE INTROSPECT_TEST') + return result[1] + + @cached_property + def can_introspect_foreign_keys(self): + "Confirm support for introspected foreign keys" + return self._mysql_storage_engine != 'MyISAM' + + @cached_property + def has_zoneinfo_database(self): + # MySQL accepts full time zones names (eg. Africa/Nairobi) but rejects + # abbreviations (eg. EAT). When pytz isn't installed and the current + # time zone is LocalTimezone (the only sensible value in this + # context), the current time zone name will be an abbreviation. As a + # consequence, MySQL cannot perform time zone conversions reliably. + if pytz is None: + return False + + # Test if the time zone definitions are installed. + cursor = self.connection.cursor() + cursor.execute("SELECT 1 FROM mysql.time_zone LIMIT 1") + return cursor.fetchone() is not None + +class DatabaseOperations(BaseDatabaseOperations): + compiler_module = "django.db.backends.mysql.compiler" + + def date_extract_sql(self, lookup_type, field_name): + # http://dev.mysql.com/doc/mysql/en/date-and-time-functions.html + if lookup_type == 'week_day': + # DAYOFWEEK() returns an integer, 1-7, Sunday=1. + # Note: WEEKDAY() returns 0-6, Monday=0. + return "DAYOFWEEK(%s)" % field_name + else: + return "EXTRACT(%s FROM %s)" % (lookup_type.upper(), field_name) + + def date_trunc_sql(self, lookup_type, field_name): + fields = ['year', 'month', 'day', 'hour', 'minute', 'second'] + format = ('%%Y-', '%%m', '-%%d', ' %%H:', '%%i', ':%%s') # Use double percents to escape. + format_def = ('0000-', '01', '-01', ' 00:', '00', ':00') + try: + i = fields.index(lookup_type) + 1 + except ValueError: + sql = field_name + else: + format_str = ''.join([f for f in format[:i]] + [f for f in format_def[i:]]) + sql = "CAST(DATE_FORMAT(%s, '%s') AS DATETIME)" % (field_name, format_str) + return sql + + def datetime_extract_sql(self, lookup_type, field_name, tzname): + if settings.USE_TZ: + field_name = "CONVERT_TZ(%s, 'UTC', %%s)" % field_name + params = [tzname] + else: + params = [] + # http://dev.mysql.com/doc/mysql/en/date-and-time-functions.html + if lookup_type == 'week_day': + # DAYOFWEEK() returns an integer, 1-7, Sunday=1. + # Note: WEEKDAY() returns 0-6, Monday=0. + sql = "DAYOFWEEK(%s)" % field_name + else: + sql = "EXTRACT(%s FROM %s)" % (lookup_type.upper(), field_name) + return sql, params + + def datetime_trunc_sql(self, lookup_type, field_name, tzname): + if settings.USE_TZ: + field_name = "CONVERT_TZ(%s, 'UTC', %%s)" % field_name + params = [tzname] + else: + params = [] + fields = ['year', 'month', 'day', 'hour', 'minute', 'second'] + format = ('%%Y-', '%%m', '-%%d', ' %%H:', '%%i', ':%%s') # Use double percents to escape. + format_def = ('0000-', '01', '-01', ' 00:', '00', ':00') + try: + i = fields.index(lookup_type) + 1 + except ValueError: + sql = field_name + else: + format_str = ''.join([f for f in format[:i]] + [f for f in format_def[i:]]) + sql = "CAST(DATE_FORMAT(%s, '%s') AS DATETIME)" % (field_name, format_str) + return sql, params + + def date_interval_sql(self, sql, connector, timedelta): + return "(%s %s INTERVAL '%d 0:0:%d:%d' DAY_MICROSECOND)" % (sql, connector, + timedelta.days, timedelta.seconds, timedelta.microseconds) + + def drop_foreignkey_sql(self): + return "DROP FOREIGN KEY" + + def force_no_ordering(self): + """ + "ORDER BY NULL" prevents MySQL from implicitly ordering by grouped + columns. If no ordering would otherwise be applied, we don't want any + implicit sorting going on. + """ + return ["NULL"] + + def fulltext_search_sql(self, field_name): + return 'MATCH (%s) AGAINST (%%s IN BOOLEAN MODE)' % field_name + + def last_executed_query(self, cursor, sql, params): + # With MySQLdb, cursor objects have an (undocumented) "_last_executed" + # attribute where the exact query sent to the database is saved. + # See MySQLdb/cursors.py in the source distribution. + return force_text(getattr(cursor, '_last_executed', None), errors='replace') + + def no_limit_value(self): + # 2**64 - 1, as recommended by the MySQL documentation + return 18446744073709551615 + + def quote_name(self, name): + if name.startswith("`") and name.endswith("`"): + return name # Quoting once is enough. + return "`%s`" % name + + def random_function_sql(self): + return 'RAND()' + + def sql_flush(self, style, tables, sequences, allow_cascade=False): + # NB: The generated SQL below is specific to MySQL + # 'TRUNCATE x;', 'TRUNCATE y;', 'TRUNCATE z;'... style SQL statements + # to clear all tables of all data + if tables: + sql = ['SET FOREIGN_KEY_CHECKS = 0;'] + for table in tables: + sql.append('%s %s;' % ( + style.SQL_KEYWORD('TRUNCATE'), + style.SQL_FIELD(self.quote_name(table)), + )) + sql.append('SET FOREIGN_KEY_CHECKS = 1;') + sql.extend(self.sequence_reset_by_name_sql(style, sequences)) + return sql + else: + return [] + + def sequence_reset_by_name_sql(self, style, sequences): + # Truncate already resets the AUTO_INCREMENT field from + # MySQL version 5.0.13 onwards. Refs #16961. + if self.connection.mysql_version < (5, 0, 13): + return ["%s %s %s %s %s;" % \ + (style.SQL_KEYWORD('ALTER'), + style.SQL_KEYWORD('TABLE'), + style.SQL_TABLE(self.quote_name(sequence['table'])), + style.SQL_KEYWORD('AUTO_INCREMENT'), + style.SQL_FIELD('= 1'), + ) for sequence in sequences] + else: + return [] + + def validate_autopk_value(self, value): + # MySQLism: zero in AUTO_INCREMENT field does not work. Refs #17653. + if value == 0: + raise ValueError('The database backend does not accept 0 as a ' + 'value for AutoField.') + return value + + def value_to_db_datetime(self, value): + if value is None: + return None + + # MySQL doesn't support tz-aware datetimes + if timezone.is_aware(value): + if settings.USE_TZ: + value = value.astimezone(timezone.utc).replace(tzinfo=None) + else: + raise ValueError("MySQL backend does not support timezone-aware datetimes when USE_TZ is False.") + + # MySQL doesn't support microseconds + return six.text_type(value.replace(microsecond=0)) + + def value_to_db_time(self, value): + if value is None: + return None + + # MySQL doesn't support tz-aware times + if timezone.is_aware(value): + raise ValueError("MySQL backend does not support timezone-aware times.") + + # MySQL doesn't support microseconds + return six.text_type(value.replace(microsecond=0)) + + def year_lookup_bounds_for_datetime_field(self, value): + # Again, no microseconds + first, second = super(DatabaseOperations, self).year_lookup_bounds_for_datetime_field(value) + return [first.replace(microsecond=0), second.replace(microsecond=0)] + + def max_name_length(self): + return 64 + + def bulk_insert_sql(self, fields, num_values): + items_sql = "(%s)" % ", ".join(["%s"] * len(fields)) + return "VALUES " + ", ".join([items_sql] * num_values) + +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 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): + 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): + 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()]) |