--- In firebird-support@yahoogroups.com, "Svein Erling"
<svein.erling.tysvaer@k...> wrote:

> Hi,
> it is definitely not an SQL limit and I would be surprised if it was a
> Firebird limit (I never write statements with that many tables myself,
> but I think I once saw a statement written by Aage that contained
> about 20 tables).
>
> Though one thing you write makes me wonder. You say "behind the FROM".
> Does that mean that you are using SQL-89 (SELECT * FROM A, B WHERE A.
> ID = B.ID) and not SQL-92 (SELECT * FROM A JOIN B ON A.ID = B.ID)?
>
> If so, I'd recommend you to change to SQL-92 to see if that helps and
> report back here or to firebird-devel whether it helps or not (I
> assume having more than 16 tables in the where clause using SQL-89
> ought to work even though it must be very confusing).
>
> HTH,
> Set
> - I support Firebird, I am a FirebirdSQL Foundation member.
> - Join today at http://www.firebirdsql.org/ff/foundation
>

I use a sentence like this:
select A.ID,A.IMP,B.IMP,C.IMP,D.IMP,E.IMP,F.IMP,G.IMP,H.IMP,
J.IMP,K.IMP,L.IMP,M.IMP,N.IMP,O.IMP,P.IMP,Q.IMP
from A
left outer join B on (A.ID=B.ID)
left outer join C on (A.ID=C.ID)
left outer join D on (A.ID=D.ID)
left outer join E on (A.ID=E.ID)
left outer join F on (A.ID=F.ID)
left outer join G on (A.ID=G.ID)
left outer join H on (A.ID=H.ID)
left outer join I on (A.ID=I.ID)
left outer join J on (A.ID=J.ID)
left outer join K on (A.ID=K.ID)
left outer join L on (A.ID=L.ID)
left outer join M on (A.ID=M.ID)
left outer join N on (A.ID=N.ID)
left outer join O on (A.ID=O.ID)
left outer join P on (A.ID=P.ID)
left outer join Q on (A.ID=Q.ID)

and the error I get (from EMS ibManager):
This column cannot be updated because it is derived from an SQL
function or expression.
attempted update of read-only column.

If i put one less table I dont get the error

any idea?