Re: [Tracker] RDF Queries

[Michael Lissner <mlissner michaeljaylissner com>]

Huh. I played with this a bit more today, and it was giving me errors:

executing rdf query <rdfq:Condition>
   <rdfq:equals>
       <rdfq:Property name='Audio:Album' />
       <rdf:String>Plans</rdf:String>
   </rdfq:equals>
</rdfq:Condition>

with search term  and keyword
search term is
translated rdf query is
Select DISTINCT (S.Path || '/' || S.Name) as uri, 
GetServiceName(S.ServiceTypeID) as stype ,  S.Mime 
FROM Services S
INNER JOIN ServiceMetaData M1 ON (S.ID = M1.ServiceID and M1.MetaDataID 
in (35)) 
WHERE (S.ServiceTypeID in (select TypeId from ServiceTypes where 
TypeName = 'Music' or Parent = 'Music')) AND  (M1.MetaDataValue = ' 
'Plans' ') 
 LIMIT 0,512

ERROR: query  Select DISTINCT (S.Path || '/' || S.Name) as uri, 
GetServiceName(S.ServiceTypeID) as stype ,  S.Mime 
FROM Services S
INNER JOIN ServiceMetaData M1 ON (S.ID = M1.ServiceID and M1.MetaDataID 
in (35)) 
WHERE (S.ServiceTypeID in (select TypeId from ServiceTypes where 
TypeName = 'Music' or Parent = 'Music')) AND  (M1.MetaDataValue = ' 
'Plans' ') 
 LIMIT 0,512  failed with error: near "Plans": syntax error


I also ran tracker-extract on the mp3 file that I was expecting to get a 
hit from, and it didn't return any meta data. I'm guessing that means 
that tracker isn't gathering meta data from music files? If that's true, 
is it possible to change the config so it will?

Also, I tried to find people on IRC, but to no avail either on freenode 
(as mentioned in the thread) or Gimpnet, as mentioned on the tracker site.

Mike



Martyn Russell wrote:
> Michael Lissner wrote:
> > Any help would be appreciated, and if I can find the time, I'd be 
> > happy to work on documentation, if it's not done yet.
>
> These are some of the RDF queries we have used with tracker:
>
> #define RDF_QUERY_ALL                        \
>     "<rdfq:Condition>\n"                    \
>     "  <rdfq:and>\n"                    \
>     "    <rdfq:startsWith>\n"                \
>     "      <rdfq:Property name='File:Path' />\n"        \
>     "      <rdf:String>/</rdf:String>\n"            \
>     "    </rdfq:startsWith>\n"                \
>     "    <rdfq:not>\n"                    \
>     "      <rdfq:equals>\n"                    \
>     "        <rdfq:Property name='File:Mime' />\n"        \
>     "        <rdf:String>inode/directory</rdf:String>\n"    \
>     "      </rdfq:equals>\n"                \
>     "    </rdfq:not>\n"                    \
>     "  </rdfq:and>\n"                    \
>     "</rdfq:Condition>\n"
>
> #define RDF_QUERY_MMCS                        \
>     "<rdfq:Condition>\n"                    \
>     "  <rdfq:and>\n"                    \
>     "    <rdfq:or>\n"                    \
>     "      <rdfq:startsWith>\n"                \
>     "        <rdfq:Property name='File:Path' />\n"        \
>     "        <rdf:String>/media/mmc1</rdf:String>\n"    \
>     "      </rdfq:startsWith>\n"                \
>     "      <rdfq:startsWith>\n"                \
>     "        <rdfq:Property name='File:Path' />\n"        \
>     "        <rdf:String>/media/mmc2</rdf:String>\n"    \
>     "      </rdfq:startsWith>\n"                \
>     "    </rdfq:or>\n"                    \
>     "    <rdfq:not>\n"                    \
>     "      <rdfq:equals>\n"                    \
>     "        <rdfq:Property name='File:Mime' />\n"        \
>     "        <rdf:String>inode/directory</rdf:String>\n"    \
>     "      </rdfq:equals>\n"                \
>     "    </rdfq:not>\n"                    \
>     "  </rdfq:and>\n"                    \
>     "</rdfq:Condition>\n"
>
> #define RDF_QUERY_FOR_ARTISTS                    \
>     "<rdfq:Condition>\n"                    \
>     "  <rdfq:equals>\n"                    \
>     "    <rdfq:Property name='Audio:Artist' />\n"           \
>     "    <rdf:String>%s</rdf:String>\n"                \
>     "  </rdfq:equals>\n"                    \
>     "</rdfq:Condition>\n"
>
> #define RDF_QUERY_FOR_ALBUMS                    \
>     "<rdfq:Condition>\n"                    \
>     "  <rdfq:equals>\n"                    \
>     "    <rdfq:Property name='Audio:Album' />\n"            \
>     "    <rdf:String>%s</rdf:String>\n"            \
>     "  </rdfq:equals>\n"                    \
>     "</rdfq:Condition>\n"
>
> #define RDF_QUERY_FOR_PLAYLISTS                    \
>     "<rdfq:Condition>\n"                    \
>     "  <rdfq:equals>\n"                    \
>     "    <rdfq:Property name='Playlist:Name' />\n"          \
>     "    <rdf:String>%s</rdf:String>\n"            \
>     "  </rdfq:equals>\n"                    \
>     "</rdfq:Condition>\n"
>
> #define RDF_QUERY_FOR_TAGS                    \
>     "<rdfq:Condition>\n"                    \
>     "  <rdfq:equals>\n"                    \
>     "    <rdfq:Property name='User:Keywords' />\n"          \
>     "    <rdf:String>%s</rdf:String>\n"            \
>     "  </rdfq:equals>\n"                    \
>     "</rdfq:Condition>\n"
>
> Hope this helps. To make sure you have content worthy of being found 
> by RDF queries, remember, you have the src/tracker-utils/ applications 
> to return a bunch of information. E.g.:
>
>   tracker-stats
>   tracker-files -s Images
>   tracker-unique Audio:Artist
>   tracker-services -p
>   tracker-search mp3
>   tracker-info /path/to/file