How to use CQL_FILTER for the highest value in a layer field?

Question

I need to query/filter my wms in openlayers to only see the polygons classified with the highest values in a given field.

Would be something like:

wms_layer.mergeNewParams({'CQL_FILTER': "ND = max(ND)"});

But this is not working.

Any ideas?

Answer 1

There is no way to do that. If you want to get the highest value of a filed you have to use WPS, GeoServer has a process that does basic statistics on fields, including the max value.