path: root/docs/manpages/tracker-sparql.1.txt

tracker-sparql(1)
=================

== NAME

tracker-sparql - Use SparQL to query the Tracker databases.

== SYNOPSIS

....
tracker sparql -q <sparql> [-u] | -f <file>
tracker sparql -t [class] [-s <needle>] [-p]
tracker sparql [-c] [-p] [-x] [-n [class]] [-i [property]] [-s <needle>]
tracker sparql [--get-longhand <class>] [--get-shorthand <class>]
....

== DESCRIPTION

This command allows probing of the current database schema (also known
as ontology) and running low level queries or updates on the data set.
In terms of the database ontology, it's easy to find out what properties
are indexed for speed, or notified on changes, what classes are
available and the properties belonging to those classes. There are also
visual tools to display an ascii tree layout of the classes and their
relationships to each other.

When the caller runs a query, the query is in RDF and SPARQL. This can
be done two ways. Either by providing a _file_ with the query or by
providing a string with the _sparql_ query.

The _file_ argument can be either a local path or a URI. It also does
not have to be an absolute path.

== OPTIONS

*-f, --file=<__file__>*::
  Use a _file_ with SPARQL content to query or update.
*-q, --query=<__sparql__>*::
  Use a _sparql_ string to query the database with.
*-u, --update*::
  This has to be used with *--query*. This tells "tracker sparql" to use
  the SPARQL update extensions so it knows it isn't a regular data
  lookup request. So if your query is intended to change data in the
  database, this option is needed.
*-c, --list-classes*::
  Returns a list of classes which describe the ontology used for storing
  data. These classes are also used in queries. For example,
  _http://www.w3.org/2000/01/rdf-schema#Resource_ is one of many classes
  which should be returned here.
*-x, --list-class-prefixes*::
  Returns a list of classes and their related prefixes. Prefixes are
  used to make querying a lot simpler and are much like an alias. For
  example, _http://www.w3.org/2000/01/rdf-schema#Resource_ has the
  prefix _rdfs_ so queries can be cut down to:

"SELECT ?u WHERE \{ ?u a rdfs:Resource }"

*-p, --list-properties=[_class_]*::
  Returns a list of properties which pertain to a _class_. You can use
  both formats here for the _class_, either the full name
  _http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#Video_ or
  the shortened prefix name _nfo:Video_.

This gives the following result:

----
$ tracker sparql -p nfo:Video

Properties: 2
  http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#frameRate
  http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#frameCount
----

These properties _nfo:frameRate_ and _nfo:frameCount_ can then be used
in queries.

See also *--tree* and *--query*.

*-n, --list-notifies=[_class_]*::
  Returns a list of classes which are notified over D-Bus about any
  changes that occur in the database. The _class_ does not have to be
  supplied here. This is optional and filters the results according to
  any argument supplied. With no _class_, all classes are listed.

*-i, --list-indexes=[_property_]*::
  Returns a list of properties which are indexed in the database.
  Indexes improves query speed but also add an indexing penalty. The
  _property_ does not have to be supplied here. This is optional and
  filters the results according to any argument supplied. With no
  _property_, all properties are listed.

*-t, --tree=[_class_]*::
  Prints a tree showing all parent classes of _class_ in the ontology.
  The _class_ can be provided in shorthand or longhand (see
  *--get-shorthand* and *--get-longhand* for details). For example:

----
$ tracker sparql -t nmo:MMSMessage
ROOT
  +-- rdfs:Resource (C)
  |  +-- nie:InformationElement (C)
  |  |  +-- nfo:Document (C)
  |  |  |  +-- nfo:TextDocument (C)
  |  |  |  |  `-- nmo:Message (C)
  |  |  |  |  |  +-- nmo:PhoneMessage (C)
  |  |  |  |  |  |  `-- nmo:MMSMessage (C)
----

If no _class_ is given, the entire tree is shown.

The *--search* command line option can be used to highlight parts of the
tree you're looking for. The search is case insensitive.

The *--properties* command line option can be used to show properties
for each class displayed, for example:

----
$ tracker sparql -t nfo:FileDataObject -p
ROOT
  +-- rdfs:Resource (C)
  |  --> http://purl.org/dc/elements/1.1/contributor (P)
  |  --> http://purl.org/dc/elements/1.1/coverage (P)
  |  --> http://purl.org/dc/elements/1.1/creator (P)
  |  --> http://purl.org/dc/elements/1.1/date (P)
  |  --> http://purl.org/dc/elements/1.1/description (P)
  |  --> http://purl.org/dc/elements/1.1/format (P)
  |  --> http://purl.org/dc/elements/1.1/identifier (P)
  |  --> http://purl.org/dc/elements/1.1/language (P)
  |  --> http://purl.org/dc/elements/1.1/publisher (P)
  |  --> http://purl.org/dc/elements/1.1/relation (P)
  |  --> http://purl.org/dc/elements/1.1/rights (P)
  |  --> http://purl.org/dc/elements/1.1/source (P)
  |  --> http://purl.org/dc/elements/1.1/subject (P)
  |  --> http://purl.org/dc/elements/1.1/title (P)
  |  --> http://purl.org/dc/elements/1.1/type (P)
  |  --> nao:deprecated (P)
  |  --> nao:hasTag (P)
  |  --> nao:identifier (P)
  |  --> nao:isRelated (P)
  |  --> nao:lastModified (P)
  |  --> nao:numericRating (P)
  |  --> rdf:type (P)
  |  --> rdfs:comment (P)
  |  --> rdfs:label (P)
  |  --> tracker:added (P)
  |  --> tracker:damaged (P)
  |  --> tracker:modified (P)
  |  +-- nie:DataObject (C)
  |  |  --> nfo:belongsToContainer (P)
  |  |  --> nie:byteSize (P)
  |  |  --> nie:created (P)
  |  |  --> nie:dataSource (P)
  |  |  --> nie:interpretedAs (P)
  |  |  --> nie:isPartOf (P)
  |  |  --> nie:lastRefreshed (P)
  |  |  --> nie:url (P)
  |  |  --> tracker:available (P)
  |  |  +-- nfo:FileDataObject (C)
  |  |  |  --> nfo:fileCreated (P)
  |  |  |  --> nfo:fileLastAccessed (P)
  |  |  |  --> nfo:fileLastModified (P)
  |  |  |  --> nfo:fileName (P)
  |  |  |  --> nfo:fileOwner (P)
  |  |  |  --> nfo:fileSize (P)
  |  |  |  --> nfo:hasHash (P)
  |  |  |  --> nfo:permissions (P)
----

*-s, --search=<__needle__>*::
  Returns a list of classes and properties which partially match
  _needle_ in the ontology. This is a case insensitive match, for
  example:

----
$ tracker sparql -s text

Classes: 4
  http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#TextDocument
  http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#PlainTextDocument
  http://www.semanticdesktop.org/ontologies/2007/03/22/nfo#PaginatedTextDocument
  http://www.tracker-project.org/temp/nmm#SynchronizedText

Properties: 4
  http://www.tracker-project.org/ontologies/tracker#fulltextIndexed
  http://www.semanticdesktop.org/ontologies/2007/01/19/nie#plainTextContent
  http://www.semanticdesktop.org/ontologies/2007/03/22/nmo#plainTextMessageContent
  http://www.tracker-project.org/temp/scal#textLocation
----

See also *--tree*.

*--get-shorthand=<__class__>*::
  Returns the shorthand for a class given by a URL. For example:

----
$ tracker sparql --get-shorthand http://www.semanticdesktop.org/ontologies/2007/03/22/nmo#plainTextMessageContent
nmo:plainTextMessageContent
----

*--get-longhand=<__class__>*::
  Returns the longhand for a class given in the form of CLASS:PROPERTY.
  For example:

----
$ tracker sparql --get-longhand nmm:MusicPiece
http://www.tracker-project.org/temp/nmm#MusicPiece
----

== EXAMPLES

List all classes::
+
....
$ tracker sparql -q "SELECT ?cl WHERE { ?cl a rdfs:Class }"
....

List all properties for the Resources class (see --list-properties)::
+
----
$ tracker sparql -q "SELECT ?prop WHERE {
    ?prop a rdf:Property ;
    rdfs:domain <http://www.w3.org/2000/01/rdf-schema#Resource>
}"
----

List all class namespace prefixes::
+
----
$ tracker sparql -q "SELECT ?prefix ?ns WHERE {
    ?ns a tracker:Namespace ;
    tracker:prefix ?prefix
}"
----

List all music files::
+
----
$ tracker sparql -q "SELECT ?song WHERE { ?song a nmm:MusicPiece }"
----

List all music albums, showing title, track count, and length in seconds.::
+
----
$ tracker sparql -q "SELECT ?title COUNT(?song)
                    AS songs
                    SUM(?length) AS totallength
                    WHERE {
    ?album a nmm:MusicAlbum ;
    nie:title ?title .
    ?song nmm:musicAlbum ?album ;
    nfo:duration ?length
} GROUP BY ?album"
----

List all music from a particular artist::
+
----
$ tracker sparql -q "SELECT ?song ?title WHERE {
    ?song nmm:performer [ nmm:artistName 'Artist Name' ] ;
    nie:title ?title
}"
----

Set the played count for a song::
+
----
$ tracker sparql -u -q "DELETE {
    <file:///home/user/Music/song.mp3> nie:usageCounter ?count
} WHERE {
    <file:///home/user/Music/song.mp3> nie:usageCounter ?count
} INSERT {
    <file:///home/user/Music/song.mp3> nie:usageCounter 42
}"
----

List all image files::
+
----
$ tracker sparql -q "SELECT ?image WHERE { ?image a nfo:Image }"
----

List all image files with a specific tag::
+
----
$ tracker sparql -q "SELECT ?image WHERE {
    ?image a nfo:Image ;
    nao:hasTag [ nao:prefLabel 'tag' ]
}"
----

List all image files created on a specific month and order by date::
+
----
$ tracker sparql -q "SELECT ?image ?date WHERE {
    ?image a nfo:Image ;
    nie:contentCreated ?date .
    FILTER (?date >= '2008-07-01T00:00:00' &&
            ?date <  '2008-08-01T00:00:00')
} ORDER BY ?date"
----

== SEE ALSO

*tracker-sql*(1), *tracker-store*(1), *tracker-info*(1).

*http://nepomuk.semanticdesktop.org/*
*http://www.w3.org/TR/rdf-sparql-query/*