Title: SPARQL Tutorial - A First SPARQL Query

In this section, we look at a simple first query and show how to
execute it with Jena.

## A "hello world" of queries

The file "[q1.rq](sparql_data/q1.rq)" contains the following query:

    SELECT ?x
    WHERE { ?x  <http://www.w3.org/2001/vcard-rdf/3.0#FN>  "John Smith" }

executing that query with the command line query application;

    ---------------------------------
    | x                             |
    =================================
    | <http://somewhere/JohnSmith/> |
    ---------------------------------

This works by matching the triple pattern in the `WHERE` clause
against the triples in the RDF graph. The predicate and object of
the triple are fixed values so the pattern is going to match only
triples with those values. The subject is a variable, and there are
no other restrictions on the variable. The pattern matches any
triples with these predicate and object values, and it matches with
solutions for `x`.

The item enclosed in <\> is a URI (actually, it's an IRI) and the
item enclosed in "" is a plain literal. Just like Turtle, N3 or
N-triples, typed literals are written with \^\^ and language tags
can be added with @.

?x is a variable called x. The ? does not form part of the name
which is why it does not appear in the table output.

There is one match. The query returns the match in the `x` query
variable. The output shown was obtained by using one of ARQ's
command line applications.

## Executing the query

There are [helper scripts](/documentation/query/cmds.html) in the ARQ `bat/` and
`bin/` directories of the ARQ distribution. They may not be in a
Jena distribution. You should check these scripts before use.

### Windows setup

Set the `ARQROOT` environment variable to the file location of the
ARQ distribution.

    set ARQROOT=c:\MyProjects\ARQ

The distribution usually has the version number in the directory
name.

In the ARQ directory, execute:

    bat\sparql.bat --data=doc\Tutorial\vc-db-1.rdf --query=doc\Tutorial\q1.rq

(TODO we will need to update these once the release structure is clear)

You can just put the `bat/` directory on your classpath or copy the
programs out of it. They all depend on ARQROOT.

### bash scripts for Linux/Cygwin/Unix

Set the `ARQROOT` environment variable to the file location of the
ARQ distribution.

    export ARQROOT=$HOME/MyProjects/ARQ

The distribution usually has the version number in the directory
name.

In the ARQ directory, execute:

    bin/sparql --data=doc/Tutorial/vc-db-1.rdf --query=doc/Tutorial/q1.rq

You can just put the `bin/` directory on your classpath or copy the
programs out of it. They all depend on ARQROOT.

[Cygwin](http://www.cygwin.com/) is a Linux-like environment for
Windows.

### Using the Java command line applications directly

You will need to set the classpath to include *all* the jar files
in the ARQ `lib/` directory.

For example, on Windows:

    ARQdir\lib\antlr-2.7.5.jar;ARQdir\lib\arq-extra.jar;ARQdir\lib\arq.jar;
    ARQdir\lib\commons-logging-1.1.jar;ARQdir\lib\concurrent.jar;ARQdir\lib\icu4j_3_4.jar;
    ARQdir\lib\iri.jar;ARQdir\lib\jena.jar;ARQdir\lib\jenatest.jar;
    ARQdir\lib\json.jar;ARQdir\lib\junit.jar;ARQdir\lib\log4j-1.2.12.jar;
    ARQdir\lib\lucene-core-2.2.0.jar;ARQdir\lib\stax-api-1.0.jar;
    ARQdir\lib\wstx-asl-3.0.0.jar;ARQdir\lib\xercesImpl.jar;ARQdir\lib\xml-apis.jar

(TODO needs updating)

where `<i>ARQdir</i>` is where you unpacked ARQ. This must be all
one line.

The names of jar files sometimes changes and new jar files do get
added - do check this list with your version of ARQ.

The commands themselves are in the `arq` package.

[Next: basic patterns](sparql_basic_patterns.html)