sqlplus_commando 0.1.0

sqlplus_commando is an Oracle command line driver calling sqlplus

sqlplus\_commando
=================

Installing a Oracle driver on a machine is sometime a pain, or even
impossible. Furthermore you may want to distribute self contained
scripts that access Oracle without having to ask for additional software
installation. Finally, you may want to automate scripts to should be run
with SQL\*Plus.

**sqlplus\_commando** is a pure Python Oracle driver that calls Oracle
running *sqlplus* on the command line. It was designed so that you may
use it by dropping its module in your source tree or even copy its class
in your own source code.

Installation
------------

To install **sqlplus\_commando**, you may use one of the following
methods:

- Extract classes ``SqlplusCommando`` and ``OracleParser`` from tarball
(in file *sqlplus\_commando/sqlplus\_commando.py*) and put it in your
own source code.
- Drop its module (file *sqlplus\_commando/sqlplus\_commando.py* in the
tarball) in your source directory.
- Install it using PIP, typing ``pip install sqlplus_commando``.
- Install from tarball typing ``python setup.py install``.

The Apache license grants you a right to use this driver in any of your
project (even commercial) provided that you mention that you are using
**sqlplus\_commando** in your copyright notice.

Usage
-----

You can use this driver in your code just like so::

.. code:: python

from sqlplus_commando import SqlplusCommando

mysql = SqlplusCommando(hostname='localhost', database='test',
username='test', password='test')
result = mysql.run_query("SELECT 42 AS response, 'This is a test' AS question FROM DUAL;")
print result

When query returns nothing (after an ``INSERT`` for instance), method
``run_query()`` will return an empty tuple ``()``. If query returns a
result set, this will be a tuple of dictionaries. For instance, previous
sample code could print:

.. code:: python

({'RESPONSE': 42, 'QUESTION': 'This is a test'},)

Instead of running a query you may run a script as follows::

.. code:: python

result = mysql.run_script('my_script.sql')

Parameters
----------

You can have values such as ``%(foo)s`` in you query that will be
replaced with corresponding value of the parameters dictionary. For
instance::

.. code:: python

from mysql_commando import MysqlCommando

mysql = MysqlCommando(hostname='localhost', database='test',
username='test', password='test')
parameters = {'name': 'reglisse'}
result = mysql.run_query(query="SELECT * FROM animals WHERE name=%(name)s",
parameters=parameters)
print result

You may not provide parameters running a script. To do so, call
``run_query()`` with parameters passing query
``open('my_script.sql').read()``.

Result set types
----------------

**mysql\_commando** performs auto casting before returning result sets.
As it calls MySQL on command line, every value in the result set is a
string. For convenience, it casts integers, floats, dates and NULL into
native Python types.

There are situations where this might not be accurate. For instance, if
a column is of SQL type ``VARCHAR(10)`` and contain phone numbers, all
its values will be casted to Python integers. It should not because
phone numbers can start with *0* and it should not be turned to integer.

To avoid this, you may pass ``cast=False`` when calling ``run_query()``
or ``run_script()``, like so:

.. code:: python

from mysql_commando import MysqlCommando

mysql = MysqlCommando(hostname='localhost', database='test',
username='test', password='test')
result = mysql.run_query("SELECT phone FROM users WHERE name='bob')", cast=False)
print result

You may also disable casting when instantiating the driver, passing
``cast=False`` to the constructor. This casting configuration will apply
on all calls to ``run_query()`` or ``run_script()`` except if you pass a
different value while calling these methods.

Error management
----------------

While running a query or a script with *sqlplus*, you must add following
SQL commands so that the return value is différent from *0*:

.. code:: sql

WHENEVER SQLERROR EXIT SQL.SQLCODE;
WHENEVER OSERROR EXIT 9;

These lines are added before queries or script to run to avoid having to
parse the result for error messages. Nevertheless, there are some cases
when these lines won't help for error detection. For instance, following
query:

.. code:: sql

BAD SQL QUERY;

This won't result in an error in *sqlplus* and we must parse the result
for the error string ``SP2-0734: unknown command``. This is done by
default, but you may avoid this passing parameter
``check_unknown_command=False`` while calling functions ``run_query`` or
``run_script``.

Note
----

This module is not intended to replace an genuine Oracle driver that you
**SHOULD** use if you can install it on the target machine.

Enjoy!