Re: Connect without specifying a database?

On Apr 11, 2009, at 12:56 PM, Tom Lane wrote:
>
> There is no such edge case. DROP DATABASE has to be issued while
> connected to some database, and it won't let you drop the DB you're
> connected to.
>
> And CREATE DATABASE has to be issued while connected to some database,
> so createdb still has to have a default database to connect to. There
> really is no state in Postgres corresponding to "connected but not
> connected to any particular database".
>
> It does all hang together. You will need to lose a lot of MySQL
> preconceptions along the way, I fear.
>
> regards, tom lane

I think our first issue is semantics and our second is paradigm.
Hopefully I'm simply misunderstanding what you're saying, but what
sense does it make to have to connect to an unrelated DB in order to
query about others?

Basically, I have some applications that will simply use PG as a
backend. That application needs to ask the engine manager (whatever
that means in in postgres speak) and see if relevant databases already
exist. If they don't then it needs to create them. So, how does
needing to connect to a database before querying about existing
databases make any sense? MySQL aside, it seems an extra constraint/
step for naught.

Perhaps I asked the wrong question in the beginning -- I do
apologize. Maybe I should have asked for an external application that
has the ability to talk to the PG engine. I believe John R. Pierce
provided me with what I need in his last post -- that of listing DBs
via a "psql -l".

Thanks,
Michael