dibbler/sqlalchemy/dialects/mysql/zxjdbc.py

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2010-05-07 19:33:49 +02:00
"""Support for the MySQL database via Jython's zxjdbc JDBC connector.
JDBC Driver
-----------
The official MySQL JDBC driver is at
http://dev.mysql.com/downloads/connector/j/.
Connecting
----------
Connect string format:
mysql+zxjdbc://<user>:<password>@<hostname>[:<port>]/<database>
Character Sets
--------------
SQLAlchemy zxjdbc dialects pass unicode straight through to the
zxjdbc/JDBC layer. To allow multiple character sets to be sent from the
MySQL Connector/J JDBC driver, by default SQLAlchemy sets its
``characterEncoding`` connection property to ``UTF-8``. It may be
overriden via a ``create_engine`` URL parameter.
"""
import re
from sqlalchemy import types as sqltypes, util
from sqlalchemy.connectors.zxJDBC import ZxJDBCConnector
from sqlalchemy.dialects.mysql.base import BIT, MySQLDialect, MySQLExecutionContext
class _ZxJDBCBit(BIT):
def result_processor(self, dialect, coltype):
"""Converts boolean or byte arrays from MySQL Connector/J to longs."""
def process(value):
if value is None:
return value
if isinstance(value, bool):
return int(value)
v = 0L
for i in value:
v = v << 8 | (i & 0xff)
value = v
return value
return process
class MySQLExecutionContext_zxjdbc(MySQLExecutionContext):
def get_lastrowid(self):
cursor = self.create_cursor()
cursor.execute("SELECT LAST_INSERT_ID()")
lastrowid = cursor.fetchone()[0]
cursor.close()
return lastrowid
class MySQLDialect_zxjdbc(ZxJDBCConnector, MySQLDialect):
jdbc_db_name = 'mysql'
jdbc_driver_name = 'com.mysql.jdbc.Driver'
execution_ctx_cls = MySQLExecutionContext_zxjdbc
colspecs = util.update_copy(
MySQLDialect.colspecs,
{
sqltypes.Time: sqltypes.Time,
BIT: _ZxJDBCBit
}
)
def _detect_charset(self, connection):
"""Sniff out the character set in use for connection results."""
# Prefer 'character_set_results' for the current connection over the
# value in the driver. SET NAMES or individual variable SETs will
# change the charset without updating the driver's view of the world.
#
# If it's decided that issuing that sort of SQL leaves you SOL, then
# this can prefer the driver value.
rs = connection.execute("SHOW VARIABLES LIKE 'character_set%%'")
opts = dict((row[0], row[1]) for row in self._compat_fetchall(rs))
for key in ('character_set_connection', 'character_set'):
if opts.get(key, None):
return opts[key]
util.warn("Could not detect the connection character set. Assuming latin1.")
return 'latin1'
def _driver_kwargs(self):
"""return kw arg dict to be sent to connect()."""
return dict(characterEncoding='UTF-8', yearIsDateType='false')
def _extract_error_code(self, exception):
# e.g.: DBAPIError: (Error) Table 'test.u2' doesn't exist
# [SQLCode: 1146], [SQLState: 42S02] 'DESCRIBE `u2`' ()
m = re.compile(r"\[SQLCode\: (\d+)\]").search(str(exception.orig.args))
c = m.group(1)
if c:
return int(c)
def _get_server_version_info(self,connection):
dbapi_con = connection.connection
version = []
r = re.compile('[.\-]')
for n in r.split(dbapi_con.dbversion):
try:
version.append(int(n))
except ValueError:
version.append(n)
return tuple(version)
dialect = MySQLDialect_zxjdbc