Performing join on simultaneous spatial and attribute criteria in ArcGIS for Desktop?

Question

I have two point layers and want to perform a spatial join on nearest distance.

Normally it is easy with ArcMap. But now I have a restricting condition on the spatial join. The restriction only allows the attributes to be joined if the nearest point is within the same country.

Both point layers have information about the country in their attribute table (e.g., "de" for Germany). So it must be some spatial join like:

Join attribute B to layer A on nearest distance where countryID_Layer A = countryID_Layer B.

Does anybody have an idea how I could solve this?

EDIT: Image I have following attributes: Table1(hotels): h_key, l_iso_a2, geom and in Table2(iata_codes): loc, ctry, geom

EDIT2: I tried to write the SQL-Statement, but it does not work somehow. Can anybody help me with this statement?:

select distinct on (h.h_key) h.h_key, h.l_iso_a2, i.loc, i.ctry, distance
from ( select h.h_key, h.l_iso_a2, i.loc, i.ctry as country2, st_distance (h.geom,
i.geom) as distance 
from hotels AS h, iata_codes AS i 
where h.l_iso_a2 = i.ctry order by h.geom <-> i.geom ) as iata_codes_h_key;

Answer 1

I think the Comment by @Brad Nesom provides an Answer with minimal steps to do what you want but may process a lot of data that gets deleted at the end.

For an alternative with more steps but less processing you could try this:

1. Iterate through your countries (using ModelBuilder or Python) one at a time to Select out your points for that country.
2. Run your Spatial Join on each country's data
3. Append your data for each country into a whole world dataset

Answer 2

In postgres it would be something like

select 
   distinct on (t2.point1_attribute) t2.point1_attribute, t2.country, t2.point2_attribute, t2.country2, t2.distance
from
  (
  select t1.point1_attribute, t1.country, t2.point2_attribute, t2.country as country2, st_distance (t1.geom, t2.geom) as distance
  from poin1 t1, point t2
  where t1.country = t2.country
  order by t1.geom  t2.geom
 ) 
as t2

Hope this helps

Answer 3

Found it. This helps:

with dist_min as ( 
select h.gid, min(st_distance(h.geom, i.geom)) dist_min from t1 h, t2 i 
where h.country = i.country 
group by h.gid 
) 
select h.attribute1, h.gid, i.attribute1, i.gid, d.dist_min from dist_min d, t1 h, t2 i 
where st_distance(h.geom, i.geom) = dist_min 
order by h.attribute1