mapscript - queryByAttributes: Aborted

[Jachym Cepicky]

Hi,

I work with perl-mapscript, after line with

[...]
    $layerObj->queryByAttributes($mapObj, "n_leg", "2240",$mapscript::MS_SINGLE);
[...]
    
I get only

$ ./mapscript.pl
*** glibc detected *** double free or corruption (!prev): 0x083eb1a8 ***
Aborted
$

I would like to write application, which would enable to find map
objects defined by attribut in database table, I suppose,
queryByAttribute is the method, I'm looking for.

I thing, I will have to do it like follows:

1) set up map extent to fulll extent
2) create layerObj
3) $layerObj->queryByAttributes($mapObj, "column name", "value",$mapscript::MS_SINGLE);
4) $resultCacheObj = $layerObj->getResults();
5) new EXTENT = $resultCacheObj->{0}->{bounds};

is there some better way, how to do this?
how does exactly drawQuery work -- are there any exaples?

I'm following the documentation from
http://zcologia.com/mapserver/mapscript, is there some better place,
where to look?

Thank you 

Jachym
    
-- 
Jachym Cepicky
e-mail: jachym.cepicky at centrum.cz
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