On Mon, Oct 24, 2011 at 12:34 PM, Giovanni Manghi <[email protected]> wrote: > Hi all, > > in a shapefile is I try to select all the records with a NULL value > > [field]= 'NULL' > > QGIS select instead the ones with value = 0. > > Is this expected?
Giovanni, the NULL value is a special one - in your example above you are actually searching for string 'NULL'. The correct expression would be: myfield IS NULL btw. In current development version (i.e. post 1.7) there is improved support for NULL values and generally three-value logic (true/false/unknown) as used in SQL. So some expressions that involve null values may give different outcomes. Regards Martin _______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
