""" MySQL database backend for Django. Requires MySQLdb: http://sourceforge.net/projects/mysql-python """ from django.db.backends import BaseDatabaseWrapper, BaseDatabaseFeatures, BaseDatabaseOperations, util try: import MySQLdb as Database except ImportError, e: from django.core.exceptions import ImproperlyConfigured raise ImproperlyConfigured("Error loading MySQLdb module: %s" % e) # 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 from MySQLdb.constants import FIELD_TYPE import re # Raise exceptions for database warnings if DEBUG is on from django.conf import settings if settings.DEBUG: from warnings import filterwarnings filterwarnings("error", category=Database.Warning) DatabaseError = Database.DatabaseError IntegrityError = Database.IntegrityError # MySQLdb-1.2.1 supports the Python boolean type, and only uses datetime # module for time-related columns; older versions could have used mx.DateTime # or strings if there were no datetime module. However, MySQLdb still 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. 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, }) # 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 DatabaseFeatures(BaseDatabaseFeatures): autoindexes_primary_keys = False inline_fk_references = False empty_fetchmany_value = () update_can_self_select = False class DatabaseOperations(BaseDatabaseOperations): def date_extract_sql(self, lookup_type, field_name): # http://dev.mysql.com/doc/mysql/en/date-and-time-functions.html 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 drop_foreignkey_sql(self): return "DROP FOREIGN KEY" def fulltext_search_sql(self, field_name): return 'MATCH (%s) AGAINST (%%s IN BOOLEAN MODE)' % field_name def limit_offset_sql(self, limit, offset=None): # 'LIMIT 20,40' sql = "LIMIT " if offset and offset != 0: sql += "%s," % offset return sql + str(limit) def no_limit_value(self): # 2**64 - 1, as recommended by the MySQL documentation return 18446744073709551615L 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): # 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;') # 'ALTER TABLE table AUTO_INCREMENT = 1;'... style SQL statements # to reset sequence indices sql.extend(["%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]) return sql else: return [] class DatabaseWrapper(BaseDatabaseWrapper): features = DatabaseFeatures() ops = DatabaseOperations() 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, **kwargs): super(DatabaseWrapper, self).__init__(**kwargs) self.server_version = None 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, settings): if not self._valid_connection(): kwargs = { 'conv': django_conversions, 'charset': 'utf8', 'use_unicode': True, } if settings.DATABASE_USER: kwargs['user'] = settings.DATABASE_USER if settings.DATABASE_NAME: kwargs['db'] = settings.DATABASE_NAME if settings.DATABASE_PASSWORD: kwargs['passwd'] = settings.DATABASE_PASSWORD if settings.DATABASE_HOST.startswith('/'): kwargs['unix_socket'] = settings.DATABASE_HOST elif settings.DATABASE_HOST: kwargs['host'] = settings.DATABASE_HOST if settings.DATABASE_PORT: kwargs['port'] = int(settings.DATABASE_PORT) kwargs.update(self.options) self.connection = Database.connect(**kwargs) cursor = 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