[firebird-support] CTE Recursive left join problem

[Germán Balbi bal...@yahoo.com [firebird-support]]

Hello everyoneI'm having a problem, and I do not understand why.I have a 
structure similar to:
with recursive
 aux as (
  select 0 as n
    from rdb$database  union all  select aux.n + 1
    from aux
    where aux.n <= 20
 )
 select aux.n, mytable.id
 from aux
   LEFT JOIN mytable on aux.n between mytable.id and mytable.id +1  where 
mytable.id is not null
Where the left join behaves as join.
Any condition that I put in the clause WHERE referred to mytable, converts the 
LEFT JOIN into JOIN