crash 0.11.0

The Crate Data Shell

.. image:: https://cdn.crate.io/web/1.0.0/img/logo-solid.png
:width: 155px
:height: 45px
:alt: Crate
:target: https://crate.io

.. image:: https://travis-ci.org/crate/crash.svg?branch=master
:target: https://travis-ci.org/crate/crash
:alt: Test

.. image:: https://badge.fury.io/py/crash.png
:target: http://badge.fury.io/py/crash
:alt: Version

.. image:: https://pypip.in/download/crash/badge.png
:target: https://pypi.python.org/pypi/crash/
:alt: Downloads

========
Overview
========

This is the Crate Data shell called ``crash``.

Installation
============

Installing via pip
------------------

To install crash via `pip <https://pypi.python.org/pypi/pip>`_ use
the following command::

$ pip install crash

To update use::

$ pip install -U crash

If you are using python 2.6 and pip >= 1.5 you have to pass the
allow-external argument::

$ pip install crash --allow-external argparse

Standalone
----------

There is also a single file executable that includes all dependencies and can
be run as long as python (>= 2.6) is available on the system.

`Download Crash bundle
<https://cdn.crate.io/downloads/releases/crash_standalone_latest>`_

The bundle can then be executed using python::

python ./crash_standalone_latest

Or::

chmod +x ./crash_standalone_latest
./crash_standalone_latest

Invocation
----------

If the package was installed using `pip` the shell can be started by
running the command `crash` in a terminal.

For usage information and command line options invoke::

crash --help

Where to go from here?
======================

to take a look at the documentation visit
`https://crate.io/docs/projects/crash/stable/ <https://crate.io/docs/projects/crash/stable/>`_.

Are you a Developer?
====================

You can build Crash on your own with the latest version hosted on GitHub.
To do so, please refer to ``DEVELOP.rst`` for further information.

Help & Contact
==============

Do you have any questions? Or suggestions? We would be very happy
to help you. So, feel free to swing by our IRC channel #crate on Freenode_.
Or for further information and official contact please
visit `https://crate.io/ <https://crate.io/>`_.

.. _Freenode: http://freenode.net

License
=======

Copyright 2013-2014 CRATE Technology GmbH ("Crate")

Licensed to CRATE Technology GmbH ("Crate") under one or more contributor
license agreements. See the NOTICE file distributed with this work for
additional information regarding copyright ownership. Crate licenses
this file to you under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License. You may
obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
License for the specific language governing permissions and limitations
under the License.

However, if you have executed another commercial license agreement
with Crate these terms will supersede the license and you may use the
software solely pursuant to the terms of the relevant commercial agreement.

====================
Installation & Usage
====================

If the package was installed using ``pip`` the shell can be started by
invoking ``crash`` in a terminal.

::

pip install crash


``crash`` by default will try to connect to ``localhost:4200``. To connect to
another host use the ``connect`` command inside the shell or use the ``--hosts``
argument when launching the shell.

``crash`` started with the ``-v`` switch (once or more times) will log useful information
when it comes to debugging, like what connection attempts are made and full tracebacks
of server errors.

For more information about the available command line arguments see :doc:`cli`.

When you connect to a server that is not reachable or whose hostname cannot be resolved
you will get an error::

cr> \connect 127.0.0.1:65535
+------------------------+-----------+---------+-----------+-----------...-+
| server_url | node_name | version | connected | message |
+------------------------+-----------+---------+-----------+-----------...-+
| http://127.0.0.1:65535 | NULL | 0.0.0 | FALSE | Server not... |
+------------------------+-----------+---------+-----------+-----------...-+
CONNECT ERROR

::

cr> \connect null.lol:4200
+----------------------+-----------+---------+-----------+-------------...-+
| server_url | node_name | version | connected | message |
+----------------------+-----------+---------+-----------+-------------...-+
| http://null.lol:4200 | NULL | 0.0.0 | FALSE | Server not a... |
+----------------------+-----------+---------+-----------+-------------...-+
CONNECT ERROR

Successful connects will give you some information about the servers you connect to::

cr> \connect 127.0.0.1:44209
+------------------------+-----------+---------+-----------+---------+
| server_url | node_name | version | connected | message |
+------------------------+-----------+---------+-----------+---------+
| http://127.0.0.1:44209 | crate | ... | TRUE | OK |
+------------------------+-----------+---------+-----------+---------+
CONNECT OK

If you connect to more than one server, the command will succeed
if at least one server is reachable::

cr> \connect 127.0.0.1:44209 null.lol:4295
+------------------------+-----------+---------+-----------+-----------...-+
| server_url | node_name | version | connected | message |
+------------------------+-----------+---------+-----------+-----------...-+
| http://127.0.0.1:44209 | crate | ... | TRUE | OK |
| http://null.lol:4295 | NULL | 0.0.0 | FALSE | Server not... |
+------------------------+-----------+---------+-----------+-----------...-+
CONNECT OK

Once the shell is connected, SQL statements can be executed simply by entering
them without any special arguments like this::

cr> SELECT schema_name, table_name FROM information_schema.tables
... ORDER BY table_name;
+--------------------+-------------------+
| schema_name | table_name |
+--------------------+-------------------+
| sys | cluster |
| information_schema | columns |
| sys | jobs |
| sys | jobs_log |
| sys | nodes |
| sys | operations |
| sys | operations_log |
| information_schema | routines |
| information_schema | schemata |
| sys | shards |
| information_schema | table_constraints |
| information_schema | table_partitions |
| information_schema | tables |
+--------------------+-------------------+
SELECT 13 rows in set (... sec)


Limitations
===========

Nested Objects and Arrays
-------------------------

.. note::

Since crate 0.39.0 it is possible to use object and array literals and the
limitation does not apply when connecting to a crate instance running > 0.39.0.

While it is possible to select or filter by nested objects it is currently not
possible to insert them using crash. In order to do that the `Crate REST
endpoint`_ or a client library like `crate-python`_ has to be used.

The same also applies for arrays.

.. _`Crate REST endpoint`: https://crate.io/docs/current/sql/rest.html
.. _`crate-python`: https://pypi.python.org/pypi/crate/