sysdbql(7)
==========
Sebastian "tokkee" Harl <sh@tokkee.org>
version {package_version}, {build_date}
:doctype: manpage

NAME
----
sysdbql - the SysDB query language

SYNOPSIS
--------

  LIST;

  QUERY hosts WHERE attribute.architecture = 'amd64';

DESCRIPTION
-----------
include::sysdb-description.txt[]

The SysDB query language is a human-readable format for describing a request
to retrieve data from a SysDB daemon. It is very remotely similar to the
Standard Query Language (SQL) supported by relational database management
systems (RDBMS) but specialized for SysDB's use-case.

QUERY COMMANDS
--------------
Each command is terminated by a semicolon. The following commands are
available to retrieve information from SysDB:

*LIST*::
Retrieve a sorted (by name) list of all hosts currently stored in SysDB. The
return value is a list of hosts where each host description includes its name,
the timestamp of the last update of the object in SysDB and an approximation
of the interval with which the host was updated.

*FETCH* '<hostname>'::
Retrieve detailed information about the specified host object. The return
value includes the hostname, a list of services referenced by the host, and a
list of attributes for the host and each service. If the host does not exist,
an error is returned.

*LOOKUP* hosts *WHERE* '<search_condition>'::
Retrieve detailed information about all host objects matching the specified
search condition. The return value is a list of detailed information for each
matching host providing the same details as returned by the *FETCH* command.
See the section "WHERE clause" for more details about how to specify the
search condition.

WHERE clause
~~~~~~~~~~~~
The *WHERE* clause in a query specifies a boolean expression which is used to
match host objects based on their names, their attributes, or services
referenced by the host. Each *WHERE* clause may be made up of one or multiple
subexpressions each matching on one criteria. The following subexpressions
are supported by SysDB:

'<field>' '<operator>' '<value>'::
	Match a named field against the specified value. See below for what fields
	and operators are supported.

*NOT* '<subexpression>'::
	Invert the boolean result of the specified subexpression.

'<subexpression>' *AND* '<subexpression>'::
'<subexpression>' *OR* '<subexpression>'::
	Combine multiple subexpressions using logical AND or logical OR.

The following fields may be queried:

*host.name*::
	The full name of the host.

*service.name*::
	The full service name as referenced by the host.

*attribute.name*::
	The full name of a host attribute.

*attribute.*'<name>'::
	The value of the named host attribute. If an attribute of the specified
	does not exist, each comparison is treated as if the value does not match.

The following operators may be used to match field values:

*=*::
	Evaluates to true if the field value exactly matches the specified value.

*!=*::
	Evaluates to true if the field value does not match the exact specified
	value.

*=~*::
	Evaluates to true if the field value matches the specified regular
	expression. SysDB uses POSIX extended regular expressions.

*!~*::
	Evalues to true if the field value does not match the specified regular
	expression.

RESPONSE FORMAT
---------------
The JavaScript Object Notation (JSON) format, as specified in RFC 4627, is
used in all replies from the server. http://www.ietf.org/rfc/rfc4627.txt

EXAMPLES
--------
The following examples illustrate the use of the commands and what their
replies look like. The replies are pretty-printed to more easily follow them.

  LIST;
  {"hosts":[{
      "name": "host1.example.com",
      "last_update": "2001-02-03 04:05:06 +0700",
      "update_interval": "5m4s"
    },{
      "name": "host2.example.com",
      "last_update": "2001-02-03 04:05:06 +0700",
      "update_interval": "5m4s"
    }]}

  FETCH 'host1.example.com';
  {
      "name": "host1.example.com",
      "last_update": "2001-02-03 04:05:06 +0700",
      "update_interval": "5m4s",
      "attributes": [{
          "name": "architecture",
          "value": "amd64",
          "last_update": "2001-02-03 04:05:06 +0700",
          "update_interval": "5m4s"
        },{
          ...
        }],
      "services": [{
          "name": "some service",
          "last_update": "2001-02-03 04:05:06 +0700",
          "update_interval": "5m4s"
        },{
          ...
        }]}

  LOOKUP hosts WHERE attribute.architecture = 'amd64';
  [{
      "name": "host1.example.com",
      "last_update": "2001-02-03 04:05:06 +0700",
      "update_interval": "5m4s",
      "attributes": [{
          "name": "architecture",
          "value": "amd64",
          "last_update": "2001-02-03 04:05:06 +0700",
          "update_interval": "5m4s"
        },{
          ...
        }],
      "services": [{
          "name": "some service",
          "last_update": "2001-02-03 04:05:06 +0700",
          "update_interval": "5m4s"
        },{
          ...
    }]},{
      ...
    }]

SEE ALSO
--------
*sysdb*(1)

AUTHOR
------
SysDB was written by Sebastian "tokkee" Harl <sh@tokkee.org>.

COPYRIGHT
---------
Copyright (C) 2012-2014 Sebastian "tokkee" Harl <sh@tokkee.org>

This is free software under the terms of the BSD license, see the source for
copying conditions. There is NO WARRANTY; not even for MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.

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