django1/django/db/backends/mysql/base.py

233 lines
7.6 KiB
Python

"""
MySQL database backend for Django.
Requires MySQLdb: http://sourceforge.net/projects/mysql-python
"""
from django.db.backends import util
try:
import MySQLdb as Database
except ImportError, e:
from django.core.exceptions import ImproperlyConfigured
raise ImproperlyConfigured, "Error loading MySQLdb module: %s" % e
from MySQLdb.converters import conversions
from MySQLdb.constants import FIELD_TYPE
import types
import re
DatabaseError = Database.DatabaseError
django_conversions = conversions.copy()
django_conversions.update({
types.BooleanType: util.rev_typecast_boolean,
FIELD_TYPE.DATETIME: util.typecast_timestamp,
FIELD_TYPE.DATE: util.typecast_date,
FIELD_TYPE.TIME: util.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). 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})')
# This is an extra debug layer over MySQL queries, to display warnings.
# It's only used when DEBUG=True.
class MysqlDebugWrapper:
def __init__(self, cursor):
self.cursor = cursor
def execute(self, sql, params=()):
try:
return self.cursor.execute(sql, params)
except Database.Warning, w:
self.cursor.execute("SHOW WARNINGS")
raise Database.Warning, "%s: %s" % (w, self.cursor.fetchall())
def executemany(self, sql, param_list):
try:
return self.cursor.executemany(sql, param_list)
except Database.Warning, w:
self.cursor.execute("SHOW WARNINGS")
raise Database.Warning, "%s: %s" % (w, self.cursor.fetchall())
def __getattr__(self, attr):
if self.__dict__.has_key(attr):
return self.__dict__[attr]
else:
return getattr(self.cursor, attr)
try:
# Only exists in Python 2.4+
from threading import local
except ImportError:
# Import copy of _thread_local.py from Python 2.4
from django.utils._threading_local import local
class DatabaseWrapper(local):
def __init__(self, **kwargs):
self.connection = None
self.queries = []
self.server_version = None
self.options = kwargs
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):
from django.conf import settings
if not self._valid_connection():
kwargs = {
'user': settings.DATABASE_USER,
'db': settings.DATABASE_NAME,
'passwd': settings.DATABASE_PASSWORD,
'conv': django_conversions,
}
if settings.DATABASE_HOST.startswith('/'):
kwargs['unix_socket'] = settings.DATABASE_HOST
else:
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()
if self.connection.get_server_info() >= '4.1':
cursor.execute("SET NAMES 'utf8'")
else:
cursor = self.connection.cursor()
if settings.DEBUG:
return util.CursorDebugWrapper(MysqlDebugWrapper(cursor), self)
return cursor
def _commit(self):
self.connection.commit()
def _rollback(self):
if self.connection:
try:
self.connection.rollback()
except Database.NotSupportedError:
pass
def close(self):
if self.connection is not None:
self.connection.close()
self.connection = None
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
supports_constraints = True
def quote_name(name):
if name.startswith("`") and name.endswith("`"):
return name # Quoting once is enough.
return "`%s`" % name
dictfetchone = util.dictfetchone
dictfetchmany = util.dictfetchmany
dictfetchall = util.dictfetchall
def get_last_insert_id(cursor, table_name, pk_name):
return cursor.lastrowid
def get_date_extract_sql(lookup_type, table_name):
# lookup_type is 'year', 'month', 'day'
# http://dev.mysql.com/doc/mysql/en/date-and-time-functions.html
return "EXTRACT(%s FROM %s)" % (lookup_type.upper(), table_name)
def get_date_trunc_sql(lookup_type, field_name):
# lookup_type is 'year', 'month', 'day'
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 get_limit_offset_sql(limit, offset=None):
sql = "LIMIT "
if offset and offset != 0:
sql += "%s," % offset
return sql + str(limit)
def get_random_function_sql():
return "RAND()"
def get_deferrable_sql():
return ""
def get_fulltext_search_sql(field_name):
return 'MATCH (%s) AGAINST (%%s IN BOOLEAN MODE)' % field_name
def get_drop_foreignkey_sql():
return "DROP FOREIGN KEY"
def get_pk_default_value():
return "DEFAULT"
def get_sql_flush(style, tables, sequences):
"""Return a list of SQL statements required to remove all data from
all tables in the database (without actually removing the tables
themselves) and put the database in an empty 'initial' state
"""
# 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;'] + \
['%s %s;' % \
(style.SQL_KEYWORD('TRUNCATE'),
style.SQL_FIELD(quote_name(table))
) for table in tables] + \
['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(quote_name(sequence['table'])),
style.SQL_KEYWORD('AUTO_INCREMENT'),
style.SQL_FIELD('= 1'),
) for sequence in sequences])
return sql
else:
return []
OPERATOR_MAPPING = {
'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',
}