Re: [arc-dev] Bug with GRAPH and OPTIONAL
From: Mario Volke
Subject: Re: [arc-dev] Bug with GRAPH and OPTIONAL
Date: Wed, 17 Dec 2008 18:21:18 +0100
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It leads to simmilar effects, I've already tried it.<br>
<br>
Unfortunately a query like the following one is also not possible:<br>
<br>
PREFIX foaf: <a class="moz-txt-link-rfc2396E" href="http://xmlns.com/foaf/0.1/"><http://xmlns.com/foaf/0.1/></a><br>
<br>
SELECT ?s ?name WHERE {<br>
GRAPH <urn:identity> {<br>
OPTIONAL { ?s foaf:givenname ?name }<br>
}<br>
}<br>
<br>
I'm getting the following error:<br>
Error: You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use
near 'LEFT JOIN origo_triple T_0_0_0_0_0_0 ON ( ((T_0_0_0_0_0_0.p =
802) /* <a class="moz-txt-link-freetext" href="http://x">http://x</a>' at line 9 via ARC2_StoreSelectQueryHandler<br>
<br>
I simply want to load a lot of different objects, but I don't know if
they are set.<br>
And I want to do this in one select-statement. So I don't see an
alternative.<br>
<br>
<br>
<br>
Benjamin Nowack schrieb:
<blockquote cite="mid:PM-GA.20081217180931.6EC7D.1.1D@semsol.com"
type="cite">
<pre wrap="">
Hi Mario,
Thanks for the bug report. OPTIONALS in combination with non-optional
restrictions are hard to translate to SQL and not fully supported.
It *might* work when you replace the GRAPH with a FROM, but it may
lead to similar (non-correct) SQL.
Benji
--
Benjamin Nowack
<a class="moz-txt-link-freetext" href="http://bnode.org/">http://bnode.org/</a>
On 17.12.2008 10:13:51, Mario Volke wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Hi,
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">I think I've found a critical bug in the sparql implementation of ARC2.
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">I've done the following queries:
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">PREFIX foaf: <a class="moz-txt-link-rfc2396E" href="http://xmlns.com/foaf/0.1/"><http://xmlns.com/foaf/0.1/></a>
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">INSERT INTO <urn:identity> {
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap=""><a class="moz-txt-link-rfc2396E" href="http://www.example.com"><http://www.example.com></a> rdf:type foaf:Person .
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap=""><a class="moz-txt-link-rfc2396E" href="http://www.example.com"><http://www.example.com></a> foaf:givenname "Anna" .
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">}
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">consider the graph uri in the following statement!!!
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">PREFIX foaf: <a class="moz-txt-link-rfc2396E" href="http://xmlns.com/foaf/0.1/"><http://xmlns.com/foaf/0.1/></a>
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">INSERT INTO <urn:identy> {
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap=""><a class="moz-txt-link-rfc2396E" href="http://www.example.com"><http://www.example.com></a> foaf:givenname "Max" .
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">}
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<pre wrap=""><!---->
</pre>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">PREFIX foaf: <a class="moz-txt-link-rfc2396E" href="http://xmlns.com/foaf/0.1/"><http://xmlns.com/foaf/0.1/></a>
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">SELECT ?s ?name WHERE {
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">GRAPH <urn:identity> {
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">?s rdf:type foaf:Person .
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">OPTIONAL { ?s foaf:givenname ?name }
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">}
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">}
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">the last select query gives me the following result:
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">s
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">name
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap=""><a class="moz-txt-link-freetext" href="http://www.example.com">http://www.example.com</a>
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">Max
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap=""><a class="moz-txt-link-freetext" href="http://www.example.com">http://www.example.com</a>
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">Anna
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<pre wrap=""><!---->
</pre>
<pre wrap=""><!---->
</pre>
<blockquote type="cite">
<pre wrap="">This is obviously wrong because Max is not in the graph <urn:identity>!!!
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
<pre wrap=""><!---->
</pre>
</blockquote>
<br>
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