I guess we need a standard definition of NULL for all drivers then since I don't believe it's the same across the board. A mapserver-dev topic. Since we use char * for all attributes we could literally use NULL.
Also, often a schema will require an element, what to do with NULLs in that case? Steve >>> "Bart van den Eijnden (OSGIS)" <[EMAIL PROTECTED]> 12/6/2006 1:07:55 PM >>> Hi Steve, as I understand from previous discussions on wfs-dev, it would be best for Mapserver to leave out the attribute from the GML response in case it's null. For reference, check the threads named "null values" here: http://mail.opengeospatial.org/pipermail/wfs-dev/2006-October/ although they get a bit hard to understand .... at least for me .... :-) Best regards, Bart Steve Lime schreef: > Mateusz is most likely correct. MapServer extracts attributes and > converts when necessary (not very often). If the asterix > always represents NULL then we could represent as something else (empty > string?) in the DBF code. What does GDAL/OGR > do with NULLs in its output? > > Steve > > >>>> Mateusz Loskot <[EMAIL PROTECTED]> 12/6/2006 9:44:29 AM >>> >>>> > Bart van den Eijnden (OSGIS) wrote: > >> Hi list, >> >> I have a strange phenomenon. >> >> A shape attribute table has some null values in it (column type >> Real), for instance: >> >> OGRFeature(nap_speciaal):856 pnt_pntid (String) = 000A2510 .. >> hgt_hgtwd (Real) = (null) .. POINT (122880 487860) >> >> Using Mapserver WFS I get the following GML output: >> >> <ms:pnt_pntid>000A2510</ms:pnt_pntid> .. >> <ms:hgt_hgtwd>************************</ms:hgt_hgtwd> .. >> >> Does anybody have an idea what is causing the sequence of asterisks? >> > > Asterix is used to indicate NULL value in Shapefile attribute. > I'm completely not sure, but I suppose MS WFS driver does not handle > asterix as null but accepts it as a string value and puts into output > GML. > > Cheers > -- Bart van den Eijnden OSGIS, Open Source GIS [EMAIL PROTECTED] http://www.osgis.nl
