tracker-sparql(1) User Commands 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
ENVIRONMENT
TRACKER_SPARQL_BACKEND This option allows you to choose which backend you use for
connecting to the database. This choice can limit your
functionality. 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
separated 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 <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/GNU July 2009 tracker-sparql(1)