Alexander Farber <alexander.farber@xxxxxxxxx> writes: > why do these queries please return different results? > FROM words_scores s > LEFT JOIN words_games g ON s.gid = g.gid > AND s.uid = 1 In this one, "s.uid = 1" is part of the LEFT JOIN condition, so it never eliminates s rows. Rows not satisfying the condition will be null-extended instead. > FROM words_scores s > LEFT JOIN words_games g USING(gid) > WHERE s.uid = 1 In this one, it's part of the top-level WHERE, so it does eliminate s rows. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
