199 lines
9.3 KiB
ReStructuredText
199 lines
9.3 KiB
ReStructuredText
=================================================================
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JayDeBeApi - bridge from JDBC database drivers to Python DB-API
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=================================================================
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The JayDeBeApi module allows you to connect from Python code to
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databases using Java `JDBC
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<http://java.sun.com/products/jdbc/overview.html>`_. It provides a
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Python DB-API_ v2.0 to that database.
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It works on ordinary Python (cPython) using the JPype_ Java
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integration or on `Jython <http://www.jython.org/>`_ to make use of
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the Java JDBC driver.
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In contrast to zxJDBC from the Jython project JayDeBeApi let's you
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access a database with Jython AND Python with only minor code
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modifications. JayDeBeApi's future goal is to provide a unique and
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fast interface to different types of JDBC-Drivers through a flexible
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plug-in mechanism.
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.. contents::
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Install
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=======
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You can get and install JayDeBeApi with `easy_install
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<http://peak.telecommunity.com/DevCenter/EasyInstall>`_ ::
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$ easy_install JayDeBeApi
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If you want to install JayDeBeApi in Jython make sure to have
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EasyInstall available for it.
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Or you can get a copy of the source branch using `bzr
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<http://bazaar.canonical.com/>`_ by running ::
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$ bzr branch lp:jaydebeapi
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and install it with ::
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$ python setup.py install
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or if you are using Jython use ::
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$ jython setup.py install
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It has been tested with Jython 2.5.3.
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If you are using cPython ensure that you have installed JPype_
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properly. It has been tested with JPype 0.5.4.
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Usage
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=====
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Basically you just import the ``jaydebeapi`` Python module and execute
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the ``connect`` method. This gives you a DB-API_ conform connection to
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the database.
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The first argument to ``connect`` is the name of the Java driver
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class. Then you can supply a single argument or a sequence of
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arguments that are internally passed to the Java
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``DriverManager.getConnection`` method. Usually this is the JDBC
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connection URL. See the Javadoc of ``DriverManager`` class for
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details.
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The next parameter to ``connect`` is optional and specifies the
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jar-Files of the driver if your classpath isn't set up sufficiently
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yet. The classpath set in ``CLASSPATH`` environment variable will be
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honored. See the documentation of your Java runtime environment.
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Here is an example:
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>>> import jaydebeapi
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>>> conn = jaydebeapi.connect('org.hsqldb.jdbcDriver',
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... ['jdbc:hsqldb:mem:.', 'SA', ''],
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... '/path/to/hsqldb.jar',)
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>>> curs = conn.cursor()
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>>> curs.execute('create table CUSTOMER'
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... '("CUST_ID" INTEGER not null,'
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... ' "NAME" VARCHAR not null,'
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... ' primary key ("CUST_ID"))'
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... )
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>>> curs.execute("insert into CUSTOMER values (1, 'John')")
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>>> curs.execute("select * from CUSTOMER")
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>>> curs.fetchall()
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[(1, u'John')]
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If you're having trouble getting this work check if your ``JAVA_HOME``
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environmentvariable is set correctly. For example I have to set it on
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my Ubuntu machine like this ::
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$ JAVA_HOME=/usr/lib/jvm/java-6-openjdk python
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Supported databases
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===================
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In theory *every database with a suitable JDBC driver should work*. It
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is known to work with the following databases:
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+-----------------------------------------+------------------------------------------------+---------------+----------------------+
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|Database |JDBC driver |Supported |Remarks |
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+=========================================+================================================+===============+======================+
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|`SQLite |`SqliteJDBC |Good |Can't interpret |
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|<http://www.sqlite.org/>`_ |<http://www.zentus.com/sqlitejdbc/>`_ v056 | |selected BLOBs |
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|3 | | |correctly. |
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+-----------------------------------------+------------------------------------------------+---------------+----------------------+
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| |`Sqlite Java Wrapper |Medium |Weird type handling. |
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| |<http://www.ch-werner.de/javasqlite/>`_ | | |
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| |javasqlite-20110106-win32 | | |
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+-----------------------------------------+------------------------------------------------+---------------+----------------------+
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|`Hypersonic SQL (HSQLDB) |Builtin |Very Good |No BLOB support |
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|<http://hsqldb.org/>`_ 1.8.1.3 | | |by database. |
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| | | | |
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+-----------------------------------------+------------------------------------------------+---------------+----------------------+
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|`Hypersonic SQL (HSQLDB) |Builtin |Medium |Weird decimal |
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|<http://hsqldb.org/>`_ 2 | | |type |
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| | | |conversions. No |
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| | | |BLOB support. |
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+-----------------------------------------+------------------------------------------------+---------------+----------------------+
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|`IBM DB2 |JDBC type 4 drivers from IBM (``db2jcc.jar``) |Medium. |Not thoroughly tested |
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|<http://www.ibm.com/software/data/db2/>`_| | |but seems to work |
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|for z/OS | | |without problems. |
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+-----------------------------------------+------------------------------------------------+---------------+----------------------+
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|Oracle 11g |Oracle Thin Driver |Medium |Not thoroughly |
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| | | |tests. No support for |
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| | | |rading of timestamps |
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| | | |yet. |
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+-----------------------------------------+------------------------------------------------+---------------+----------------------+
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|Teradata DB |terajdbc4.jar |Medium |A user reported |
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| | | |success. |
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+-----------------------------------------+------------------------------------------------+---------------+----------------------+
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|Other databases |Other JDBC drivers |Unkown |Please test yourself |
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| | | |and report the |
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| | | |results. |
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+-----------------------------------------+------------------------------------------------+---------------+----------------------+
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Contributing
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============
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Please submit `bugs and patches
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<https://bugs.launchpad.net/jaydebeapi>`_. All contributors will be
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acknowledged. Thanks!
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License
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=======
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JayDeBeApi is released under the GNU Lesser General Public license
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(LGPL). See the file ``COPYING`` and ``COPYING.LESSER`` in the
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distribution for details.
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Changelog
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=========
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- 0.1.4
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- More convenient way to setup Java classpath. *Important note*
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check the changes to the ``connect`` method and adapt your code.
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- Honor ``CLASSPATH`` if used in JPype mode.
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- Set ``.rowcount`` properly.
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- Changed signature of ``.setoutputsize()`` to be DB-API compliant.
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- 0.1.3
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- Fixed DB-API_ violation: Use ``curs.execute('foo ?', (bar, baz))``
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instead of ``curs.execute('foo ?', bar, baz)``.
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- Free resources after ``executemany`` call.
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- Improved type handling. Initial support for BLOB columns.
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- 0.1.2
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- ``easy_install JayDeBeApi`` should really work.
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- 0.1.1
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- Fixed bug #688290 "NULL values with converters error on fetch".
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- Fixed bug #684909 "Selecting ROWIDs errors out on fetch".
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- 0.1
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- Initial release.
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To do
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=====
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- Extract Java calls to seperate Java methods to increase performance.
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- Check if https://code.launchpad.net/dbapi-compliance can help making
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JayDeBeApi more DB-API complient.
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- Test it on different databases and provide a flexible db specific
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pluign mechanism.
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- SQLAlchemy modules (seperate project)
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.. _DB-API: http://www.python.org/dev/peps/pep-0249/
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.. _JPype: http://jpype.sourceforge.net/
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