The Subject says it all. (author beats a hasty retreat).
Quoting Dmitri Bichko <dbichko@aveopharma.com>:
> I don't see what the problem is.
> Did you mean to insert (3,'C3') into table c, rather than b?
> > create temp table a(keyf int, val text);
> > create temp table b(keyf int, val text);
> > create temp table c(keyf int, val text);
> > insert into a values(1, 'A1');
> > insert into a values(2, 'A2');
> > insert into a values(3, 'A3');
> > insert into a values(4, 'A4');
> > insert into b values(1, 'B1');
> > insert into b values(2, 'B2');
> > insert into c values(2, 'C2');
> > insert into b values(3, 'C3');
> > select keyf, a.val as aval,
> > coalesce(b.val,'Bxx') as bval,
> > coalesce(c.val,'Cxx') as cval
> > from a left join b using(keyf) left join c using (keyf);
> > keyf aval bval cval
> > ---- ---- ---- ----
> > 1 A1 B1 Cxx
> > 2 A2 B2 C2
> > 3 A3 C3 Cxx
> > 4 A4 Bxx Cxx
