sql - Join when exact match other other wise join with default value -
i have 2 table , b table a id b c table b id value 1 b 2 default 0 so want join 2 tables on id when matching, otherwise use default value desired results id value 1 b 2 c 0 use left outer join purpose like select t1.id, coalesce(t2.value, 0) value tablea t1 left join tableb t2 on t1.id = t2.id;