Question

I have a question about using subqueries in an Update statement. My example:

UPDATE TRIPS
   SET locations = city + ', ' FROM (select Distinct city 
                                       from poi 
                                      where poi.trip_guid = trips.guid) 

Is it possible to refer to main table value (trips.guid) in subqueries?

When i try to use trips.guid I get the error:

“The multi-part identifier “trips.guid” could not be bound.”

The clause ‘select Distinct city from poi’ return more that one city.

Answer 1

You can try something like

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