CartoDB PostGIS SQL Intersect. fucking cartodb temp solution to more than one row returned error, see distinctLimitIntersect.sql. not sure if the distinct and limit are both needed, i think at least limit is needed. it won't work with distinct alone.

distinctLimitIntersect.sql

UPDATE table
  SET city_end = (
    SELECT DISTINCT cityname
    FROM cities
    WHERE ST_Intersects(the_geom, table.the_geom)
    LIMIT 1
  )

intersect.sql

UPDATE gps_end
  SET city = (
    SELECT cityname
    FROM cities
    WHERE ST_Intersects(the_geom, gps_end.the_geom)
  )