Thread

Re: Re: [SQL] aliases break my query

Zeugswetter Andreas <andreas.zeugswetter@telecom.at> — 2000-05-28T07:34:40Z

On Fri, 26 May 2000, Tom Lane wrote:
> "Zeugswetter Andreas" <andreas.zeugswetter@telecom.at> writes:
> > I think we could get agreement to not allow implicit from entries 
> > if there is a from clause in the statement, but allow them if a from clause
> > is missing altogether. The patch did not distinguish the two cases.
> 
> Hmm, that's a thought.  Taking it a little further, how about this:
> 
> "Emit a notice [or error if you insist] when an implicit FROM item is
> added that refers to the same underlying table as any existing FROM
> item."
> 
> 95% of the complaints I can remember seeing were from people who got
> confused by the behavior of "FROM table alias" combined with a reference
> like "table.column".  Seems to me the above rule would catch this case
> without being obtrusive in the useful cases.  Comments?

I guess I would be more strict on the reason, that people playing with implicit
from entries usually know what they are doing, and thus know how to avoid a from
clause if they want that behavior. I don't see a reason to have one table in the
from clause but not another. This is too misleading for me.

Andreas