mirror of
https://github.com/janeczku/calibre-web
synced 2024-12-28 02:50:30 +00:00
114 lines
4.0 KiB
Python
114 lines
4.0 KiB
Python
# firebird/fdb.py
|
|
# Copyright (C) 2005-2013 the SQLAlchemy authors and contributors <see AUTHORS file>
|
|
#
|
|
# This module is part of SQLAlchemy and is released under
|
|
# the MIT License: http://www.opensource.org/licenses/mit-license.php
|
|
|
|
"""
|
|
.. dialect:: firebird+fdb
|
|
:name: fdb
|
|
:dbapi: pyodbc
|
|
:connectstring: firebird+fdb://user:password@host:port/path/to/db[?key=value&key=value...]
|
|
:url: http://pypi.python.org/pypi/fdb/
|
|
|
|
fdb is a kinterbasdb compatible DBAPI for Firebird.
|
|
|
|
.. versionadded:: 0.8 - Support for the fdb Firebird driver.
|
|
|
|
Status
|
|
------
|
|
|
|
The fdb dialect is new and not yet tested (can't get fdb to build).
|
|
|
|
Arguments
|
|
----------
|
|
|
|
The ``fdb`` dialect is based on the :mod:`sqlalchemy.dialects.firebird.kinterbasdb`
|
|
dialect, however does not accept every argument that Kinterbasdb does.
|
|
|
|
* ``enable_rowcount`` - True by default, setting this to False disables
|
|
the usage of "cursor.rowcount" with the
|
|
Kinterbasdb dialect, which SQLAlchemy ordinarily calls upon automatically
|
|
after any UPDATE or DELETE statement. When disabled, SQLAlchemy's
|
|
ResultProxy will return -1 for result.rowcount. The rationale here is
|
|
that Kinterbasdb requires a second round trip to the database when
|
|
.rowcount is called - since SQLA's resultproxy automatically closes
|
|
the cursor after a non-result-returning statement, rowcount must be
|
|
called, if at all, before the result object is returned. Additionally,
|
|
cursor.rowcount may not return correct results with older versions
|
|
of Firebird, and setting this flag to False will also cause the
|
|
SQLAlchemy ORM to ignore its usage. The behavior can also be controlled on a
|
|
per-execution basis using the ``enable_rowcount`` option with
|
|
:meth:`.Connection.execution_options`::
|
|
|
|
conn = engine.connect().execution_options(enable_rowcount=True)
|
|
r = conn.execute(stmt)
|
|
print r.rowcount
|
|
|
|
* ``retaining`` - True by default. Leaving this on True will pass the
|
|
``retaining=True`` keyword argument to the ``.commit()`` and ``.rollback()``
|
|
methods of the DBAPI connection, which can improve performance in some
|
|
situations, but apparently with significant caveats.
|
|
Please read the fdb and/or kinterbasdb DBAPI documentation in order to
|
|
understand the implications of this flag.
|
|
|
|
.. versionadded:: 0.8.2 - ``retaining`` keyword argument specifying
|
|
transaction retaining behavior. This flag will **default to False**
|
|
in 0.9.
|
|
|
|
.. seealso::
|
|
|
|
http://pythonhosted.org/fdb/usage-guide.html#retaining-transactions - information
|
|
on the "retaining" flag.
|
|
|
|
"""
|
|
|
|
from .kinterbasdb import FBDialect_kinterbasdb
|
|
from ... import util
|
|
|
|
|
|
class FBDialect_fdb(FBDialect_kinterbasdb):
|
|
|
|
def __init__(self, enable_rowcount=True,
|
|
retaining=True, **kwargs):
|
|
super(FBDialect_fdb, self).__init__(
|
|
enable_rowcount=enable_rowcount,
|
|
retaining=retaining, **kwargs)
|
|
|
|
@classmethod
|
|
def dbapi(cls):
|
|
return __import__('fdb')
|
|
|
|
def create_connect_args(self, url):
|
|
opts = url.translate_connect_args(username='user')
|
|
if opts.get('port'):
|
|
opts['host'] = "%s/%s" % (opts['host'], opts['port'])
|
|
del opts['port']
|
|
opts.update(url.query)
|
|
|
|
util.coerce_kw_type(opts, 'type_conv', int)
|
|
|
|
return ([], opts)
|
|
|
|
def _get_server_version_info(self, connection):
|
|
"""Get the version of the Firebird server used by a connection.
|
|
|
|
Returns a tuple of (`major`, `minor`, `build`), three integers
|
|
representing the version of the attached server.
|
|
"""
|
|
|
|
# This is the simpler approach (the other uses the services api),
|
|
# that for backward compatibility reasons returns a string like
|
|
# LI-V6.3.3.12981 Firebird 2.0
|
|
# where the first version is a fake one resembling the old
|
|
# Interbase signature.
|
|
|
|
isc_info_firebird_version = 103
|
|
fbconn = connection.connection
|
|
|
|
version = fbconn.db_info(isc_info_firebird_version)
|
|
|
|
return self._parse_version_info(version)
|
|
|
|
dialect = FBDialect_fdb
|