Re: pqlib in c++: PQconnectStart PQconnectPoll

"madhtr" <madhtr(at)schif(dot)org> writes:
> cleary I am going to have to study this documentation more carefully ... So
> ... for simplicity's sake, If I just do the following, how do I get back
> "database does not exist" ?

[ shrug... ] Your program works perfectly for me:

$ ./testit
PQerrorMessage(lpcn) returns:

FATAL: database "nonexistantdb" does not exist

PQstatus(lpcn)
returns 1
$

... although it takes a good long while (several seconds) because of the
"sleep(1)" in the interaction with the postmaster.

Maybe your problem is not with the program, but with the postmaster
you're trying to connect to? Does psql work?

> source: http://www.postgresql.org/docs/7.3/static/libpq-connect.html

Another line of thought, given the reading-between-the-lines conclusion
that you are trying to use PG 7.3 libraries on Windows, is that there
was something broken in the async-connect code back then on that
platform. If you really are trying to do that, do yourself a favor and
move to 8.0 or later. Nobody's going to be very interested in fixing
7.3. (I did try your program with 7.3 on Unix, though, and it seemed
fine except the error message was spelled a bit differently.)

> I was also under the assumption that I would not need to perform my own
> selects on the underlying socket, and that whatever I got back would be
> either a null pointer, a successful connection pointer, or a broken
> connection pointer with an error indication.

You don't *have* to perform selects on the underlying socket, but if you
are not multiplexing this activity with some other I/O, I have to wonder
why you are bothering with an asynchronous connect at all. What you've
got at the moment is a poorly-implemented equivalent of PQconnectdb().

regards, tom lane