You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
113 lines
4.0 KiB
Python
113 lines
4.0 KiB
Python
# firebird/fdb.py
|
|
# Copyright (C) 2005-2022 the SQLAlchemy authors and contributors
|
|
# <see AUTHORS file>
|
|
#
|
|
# This module is part of SQLAlchemy and is released under
|
|
# the MIT License: https://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: https://pypi.org/project/fdb/
|
|
|
|
fdb is a kinterbasdb compatible DBAPI for Firebird.
|
|
|
|
.. versionchanged:: 0.9 - The fdb dialect is now the default dialect
|
|
under the ``firebird://`` URL space, as ``fdb`` is now the official
|
|
Python driver for Firebird.
|
|
|
|
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
|
|
CursorResult 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:`_engine.Connection.execution_options`::
|
|
|
|
conn = engine.connect().execution_options(enable_rowcount=True)
|
|
r = conn.execute(stmt)
|
|
print(r.rowcount)
|
|
|
|
* ``retaining`` - False by default. Setting this to 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.
|
|
|
|
.. versionchanged:: 0.9.0 - the ``retaining`` flag defaults to ``False``.
|
|
In 0.8 it defaulted to ``True``.
|
|
|
|
.. seealso::
|
|
|
|
https://pythonhosted.org/fdb/usage-guide.html#retaining-transactions
|
|
- information on the "retaining" flag.
|
|
|
|
""" # noqa
|
|
|
|
from .kinterbasdb import FBDialect_kinterbasdb
|
|
from ... import util
|
|
|
|
|
|
class FBDialect_fdb(FBDialect_kinterbasdb):
|
|
supports_statement_cache = True
|
|
|
|
def __init__(self, enable_rowcount=True, retaining=False, **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
|