crash 0.20.0

The Crate Data Shell

Overview

This is the Crate shell called crash.

Installation

Installing via pip

To install crash via pip use the following command:

$ pip install crash

To update use:

$ pip install -U crash

Standalone

There is also a single file executable that includes all dependencies and can be run as long as python (>= 2.7) is available on the system.

Download Crash bundle

The bundle can then be executed using python:

python ./crash_standalone_latest

Or:

chmod +x ./crash_standalone_latest
./crash_standalone_latest

Crash supported Python 2.6 until 0.16. Use Crash 0.16.0 if you’re running Python 2.6

Usage

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

Or consult the crash documentation 📚.

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 Community on Slack. Or for further information and official contact please visit https://crate.io/.

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. We recommend to install it to the Python user install directory to avoid unwanted dependency conflicts.

pip install --user crash

Note

If crash is installed in the Python user install directory please ensure that ~/.local/bin (Linux), or %APPDATA%\Python\<version>\Scripts (Windows) is added to the system path.

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 Command Line Arguments.

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 300.300.300.300:4200
+-----------------------------+-----------+---------+-----------+-------------...-+
| server_url                  | node_name | version | connected | message         |
+-----------------------------+-----------+---------+-----------+-------------...-+
| http://300.300.300.300:4200 |      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 300.300.300.300:4295;
+-----------------------------+-----------+---------+-----------+-----------...-+
| server_url                  | node_name | version | connected | message       |
+-----------------------------+-----------+---------+-----------+-----------...-+
| http://127.0.0.1:44209      | crate     | ...     | TRUE      | OK            |
| http://300.300.300.300:4295 | 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 table_name FROM information_schema.tables
... WHERE table_name = 'cluster';
+------------+
| table_name |
+------------+
| cluster    |
+------------+
SELECT 1 row in set (... sec)

When the Crate shell is started with the option -v debugging information will be printed:

cr> select x from y;
SQLActionException[SchemaUnknownException: Schema 'doc' unknown]
SQLActionException: NOT_FOUND 4045 SchemaUnknownException: Schema 'doc' unknown
...

Limitations

Note

Due to changes in the Information Schema of CrateDB, Crash versions <= 0.19 are not compatible with CrateDB > 0.57.

Nested Objects and Arrays

Note

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