#20 FILTER weirdness

[Marcus Cobden]

I've been using the FILTER constraint and have noticed some weirdness.
The following Queries generate different results.
The fist matches nothing for some reason, while the second matches what you might expect

SELECT ?p ?o ?t WHERE{
$uri ?p ?o . FILTER (?p != rdf:type)
?o rdf:type ?t
}

SELECT ?p ?o ?t WHERE{
$uri ?p ?o . FILTER (! (?p = rdf:type) )
?o rdf:type ?t
}

[Steve Harris]

Logged In: YES
user_id=17241
Originator: NO

How strange! Can you add the version of mysql you're using and the results of an "explain" of that query?

Thanks,
Steve

[Marcus Cobden]

Logged In: YES
user_id=1879346
Originator: YES

Server version: 4.1.20

[mc@cohen dev]$ /usr/local/bin/ts-explain -d wiki -f ascii 'PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> SELECT ?p ?o ?t WHERE{
> <http://wiki.rkbexplorer.com/id/hugh_glaser> ?p ?o . FILTER (! (?p = rdf:type))
> ?o rdf:type ?t .
> }'
Complexity: 788
SELECT v0.lexical AS `p`, v1.lexical AS `o`, v2.lexical AS `t`, v2.datatype AS t_dt, v2.language AS t_lang
FROM (SELECT t0.subject AS `o`, t2.predicate AS `p`, t0.object AS `_TV0`, t1.object AS `t`
FROM triples t0, triples t1, triples t2, symbols v0
WHERE v0.hash=t2.predicate
AND t2.predicate=v0.hash
AND NOT ((v0.hash<0 && v0.lexical="http://www.w3.org/1999/02/22-rdf-syntax-ns#type"))
AND t2.object=t0.subject
AND t2.subject=-6624406073138561458
AND t1.predicate=-5275523445234180533
AND t1.subject=t0.object
AND t0.predicate=-4085280037482734459
) AS `tmp0_7147`, symbols v0, symbols v1, symbols v2
WHERE tmp0_7147.p=v0.hash && tmp0_7147.o=v1.hash && tmp0_7147.t=v2.hash
;

[mc@cohen dev]$ /usr/local/bin/ts-explain -d wiki -f ascii 'PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> SELECT ?p ?o ?t WHERE{
> <http://wiki.rkbexplorer.com/id/hugh_glaser> ?p ?o . FILTER (?p != rdf:type)
> ?o rdf:type ?t .
> }'
Complexity: 91
SELECT v0.lexical AS `p`, v1.lexical AS `o`, v2.lexical AS `t`, v2.datatype AS t_dt, v2.language AS t_lang
FROM (SELECT t0.subject AS `o`, t2.predicate AS `p`, t0.object AS `_TV0`, t1.object AS `t`
FROM triples t0, triples t1, triples t2, symbols v0
WHERE v0.hash=t2.predicate
AND t2.predicate=v0.hash
AND (v0.hash<0 && v0.lexical!="http://www.w3.org/1999/02/22-rdf-syntax-ns#type" && v0.datatype IN (0,2,4,5,6,7))
AND t2.object=t0.subject
AND t2.subject=-6624406073138561458
AND t1.predicate=-5275523445234180533
AND t1.subject=t0.object
AND t0.predicate=-4085280037482734459
) AS `tmp0_7148`, symbols v0, symbols v1, symbols v2
WHERE tmp0_7148.p=v0.hash && tmp0_7148.o=v1.hash && tmp0_7148.t=v2.hash
;

[Steve Harris]

Logged In: YES
user_id=17241
Originator: NO

OK, the problem is the
v0.datatype IN (0,2,4,5,6,7)
production, but I'm not quite sure where it's coming from.