Du kan prova något liknande
UPDATE trips
SET locations = t.city + ', ' + poi.city
FROM trips t INNER JOIN
(
select Distinct city, trip_guid from poi
) poi ON t.trip_guid = poi.trip_guid
Du kan prova något liknande
UPDATE trips
SET locations = t.city + ', ' + poi.city
FROM trips t INNER JOIN
(
select Distinct city, trip_guid from poi
) poi ON t.trip_guid = poi.trip_guid