> where p.id_line=1 this filters rows after join was applied. Try this
select c.id_currency,max(p.modified_on) from currency c left join price_line p using (id_currency) where (p.id_line=1 or p.id_line is null) group by c.id_currency; > Hi, > This query: > select c.id_currency,max(p.modified_on) from currency c left join > price_line p using (id_currency) where p.id_line=1 group by > c.id_currency; > doesn't list all c.id_currency's, only those with a price_line. However > this one does: > select c.id_currency,max(p.modified_on) from currency c left join > price_line p on (p.id_currency = c.id_currency and p.id_line=1) group by > c.id_currency; > How come? > Thanks, > -- > Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-sql > Яндекс.Почта. Письма есть. Спама - нет. http://mail.yandex.ru/nospam/sign -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
