How Would I Write This Sql Update Query?

Say I have two tables: new_dogs <<---- CONTAINS DOGS SPOTTED TODAY --------- name breed color location found_date dog_locations <<---- CONTAINS A HISTORY OF ALL DOG

Solution 1:

UPDATE dog_locations SET thru_date =<actualdate or whichever date>FROM dog_locations dl
WHERENOTEXISTS (SELECT name, breed, location, found_date
              FROM new_dogs nd
              WHERE (nd.name = dl.name) AND (nd.breed = dl.breed)
                                    AND (nd.location = dl.location) 
                                    AND (nd.found_date = dl.from_date));

Cheers Anja

But you should really rethink your database design and follow LukLeds idea introducing a table dogs...