postgis select across polygon layers based on nearest adjacent polygon from other layer.

nearest_neighbor.sql

create table 
closest_point as 
select distinct on (a.featureid) a.featureid as image_id,
 (select b.eventid from fl_events as b order by st_distance(a.wkb_geometry,b.wkb_geometry) limit 1) as event_id,
 a.wkb_geometry from images as a,
 fl_events as b;

update images set eventid = closest_point.event_id from closest_point where images.featureid = closest_point.image_id;