 SELECT DISTINCT ON (communes.gid)
	communes.gid,
	sites_emprise.codsit,
	sites_emprise.nom_site,
	communes.numero,
	communes.nomcomun,
	round((ST_area(ST_intersection(communes.the_geom, sites_emprise.geom))/10000)::numeric,3 ) AS surf_inter_ha,
	communes.the_geom
 FROM spatial.communes, spatial.sites_emprise
 WHERE st_overlaps(communes.the_geom, sites_emprise.geom)
 ORDER BY communes.gid;
