2009/7/1 Mike Ivanov <mi...@activestate.com> > > > > LEFT outer JOIN ville ON ville.uid = bien.ref_ville > > LEFT outer JOIN freguesia_ville ON freguesia_ville.ref_ville =ville.uid > > This is not enough. You have to add this condition as well: > > AND bien.ref_ville = freguesia_ville.ref_ville > > In other words, when you link three tables by a common field, all three > relationships should be explicitly expressed, otherwise you'll have this > type of explosive row multiplication. >
Why so? Is not changing "freguesia_ville.ref_ville =ville.uid" to "freguesia_ville.ref_ville =bien.uid" enough (to prevent cases when ville.uid is null as result of join)?
