Re: [Tracker] Is this RDF query correct?

[Laurent Aguerreche <laurent aguerreche free fr>]

Le jeudi 31 aoÃt 2006 Ã 20:43 +0100, Jamie McCracken a Ãcrit :
> Laurent Aguerreche wrote:
> > Hello,
> >
> > I try to use this RDF query:
> >
> > ....
> >
> > and it fails with this message :
> >
> > Error in rdf query parse: Line 12 character 1: CONTAINS element not
> > expected here
> >
> >
> > What is the problem? How can I do a OR between numerous 'contains'
> > encapsulated itself in a AND? Is it legal?
>
> it should be but most likely its a bug.
>
> check start_element_handler in tracker-rdf-query.c
>
> the "state" variable refers to the previous entry on the query stack.
>
> looking at lines 626-628, the fail check is not expecting  </rdfq:or> 
> or any logic end state. I would guess adding :
>
> || is_end_logic (state)
>
> to the failcheck condition should make it okay. This would need to be 
> added to all the operators in that function.

Ok, you're right except it is is_end_operator(state).  :-)
(state which blocked was STATE_END_CONTAINS)


But let look this line:

if (set_error_on_fail ( state == STATE_CONDITION || is_logic (state) ||
                       ((data->current_logic_operator == LOP_AND) &&
                         is_end_operator (state)),
                       context,
                       "CONTAINS element not expected here", error)) {
        return;
}


IMHO only 'AND' operator is handled. So I replaced

  ((data->current_logic_operator == LOP_AND) && is_end_operator (state))

by

  ((data->current_logic_operator == LOP_AND ||
    data->current_logic_operator == LOP_OR)
  && is_end_operator (state))


Test for CONTAINS is currently:

state == STATE_CONDITION || is_logic (state) ||
 ((data->current_logic_operator == LOP_AND ||
   data->current_logic_operator == LOP_OR)
  && is_end_operator (state))



Now, I get that working SQL query:


Select DISTINCT Concat(S.Path, '/', S.Name)
 as uri, GetServiceName(S.ServiceTypeID)
 as stype , M0.MetaDataIndexValue
 FROM Services S
 INNER JOIN ServiceMetaData M5 ON S.ID = M5.ServiceID
 INNER JOIN ServiceMetaData M4 ON S.ID = M4.ServiceID
 INNER JOIN ServiceMetaData M3 ON S.ID = M3.ServiceID
 INNER JOIN ServiceMetaData M2 ON S.ID = M2.ServiceID
 INNER JOIN ServiceMetaData M1 ON S.ID = M1.ServiceID
 LEFT OUTER JOIN ServiceMetaData M0 ON S.ID = M0.ServiceID
  WHERE (S.ServiceTypeID between GetServiceTypeID('Files') and
GetMaxServiceTypeID('Files'))
  AND  (  (  ( MATCH (M1.MetaDataIndexValue) AGAINST ('opengl' IN
BOOLEAN MODE))
         OR  ( MATCH (M2.MetaDataIndexValue) AGAINST ('opengl' IN
BOOLEAN MODE))
         OR  ( MATCH (M3.MetaDataIndexValue) AGAINST ('opengl' IN
BOOLEAN MODE))
         OR  ( MATCH (M4.MetaDataIndexValue) AGAINST ('opengl' IN
BOOLEAN MODE))
         OR  ( MATCH (M5.MetaDataIndexValue) AGAINST ('opengl' IN
BOOLEAN MODE))  )  )
  AND (M5.MetaDataID = 1 )
  AND (M4.MetaDataID = 56 )
  AND (M3.MetaDataID = 55 )
  AND (M2.MetaDataID = 53 )
  AND (M1.MetaDataID = 52 )
  AND (M0.MetaDataID = 6 )
   LIMIT 0,512


but it returns an empty result which is impossible...



This follow RDF query returns many answers:

<rdfq:Condition>
  <rdfq:and>

    <rdfq:or>

      <rdfq:contains>
        <rdfq:Property name="File.Content" />
        <rdf:String>opengl</rdf:String>
      </rdfq:contains>
 
    </rdfq:or>

  </rdfq:and>
</rdfq:Condition>


but this one, nothing:


<rdfq:Condition>
  <rdfq:and>

    <rdfq:or>

      <rdfq:contains>
        <rdfq:Property name="Doc.Title" />
        <rdf:String>opengl</rdf:String>
      </rdfq:contains>

      <rdfq:contains>
        <rdfq:Property name="Doc.Subject" />
        <rdf:String>opengl</rdf:String>
      </rdfq:contains>

      <rdfq:contains>
        <rdfq:Property name="Doc.Keywords" />
        <rdf:String>opengl</rdf:String>
      </rdfq:contains>

      <rdfq:contains>
        <rdfq:Property name="Doc.Comments" />
        <rdf:String>opengl</rdf:String>
      </rdfq:contains>

      <rdfq:contains>
        <rdfq:Property name="File.Content" />
        <rdf:String>opengl</rdf:String>
      </rdfq:contains>
 
    </rdfq:or>

  </rdfq:and>
</rdfq:Condition>


(yes, 'and' does nothing there... I also tried without)

It acts like whether 'OR' is seen as 'AND'.



> Im afraid the parser checking of rdf query is not as good as it could be.

It could be worst... :-)



Laurent.

Attachment: end-operator-not-handled.diff
Description: Text Data