tracker-sparql Man page

tracker-sparql User Commands tracker-sparql

NAME

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

SYNOPSIS

tracker sparql -q [-u] | -f
tracker sparql -t [class] [-s ] [-p] tracker sparql [-c] [-p] [-x] [-n [class]] [-i [property]] [-s ] tracker sparql [–get-longhand ] [–get-shorthand ]

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 proper‐
ties 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 pro‐
viding 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=
Use a file with SPARQL content to query or update.

-q, –query=
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 exam‐
ple, 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 ontol‐
ogy. 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 proper‐
ties 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=
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=
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=
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

ENVIRONMENT
TRACKER_SPARQL_BACKEND
This option allows you to choose which backend you use for con‐
necting to the database. This choice can limit your functional‐
ity. There are three settings.

With “direct” the connection to the database is made directly to
the file itself on the disk, there is no intermediary daemon or
process. The “direct” approach is purely read-only.

With “bus” the tracker-store process is used to liase with the
database queuing all requests and managing the connections via
an IPC / D-Bus. This adds a small overhead BUT this is the only
approach you can use if you want to write to the database.

With “auto” the backend is decided for you, much like it would
be if this environment variable was undefined.

TRACKER_PRAGMAS_FILE
Tracker has a fixed set of PRAGMA settings for creating its
SQLite connection. With this environment variable pointing to a
text file you can override these settings. The file is a \n sep‐
arated list of SQLite queries to execute on any newly created
SQLite connection in tracker-store.

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
}”

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

$ tracker sparql -q “SELECT ?album ?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 {
nie:usageCounter ?count
} WHERE {
nie:usageCounter ?count
} INSERT {
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.

http://nepomuk.semanticdesktop.org/

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

GNU July 2009 tracker-sparql