A zone gpkg typically carries SEVERAL *_key columns — the program-area
layer has region_key, planarea_key and programarea_key — so "the first
column ending in key" picks the wrong one. That is not a cosmetic error:
taking region_key (3 values) for the program-area layer yields 3 zones
instead of 20, and, because the ordering it induces is not total, leaves ties
whose order depends on the file's feature order — so two byte-identical
layers saved in different order could fingerprint differently.
Arguments
- zone_type
one of
zone_set_key()'s types- nms
column names of the layer