Anton Maksimenkov <anton200(at)gmail(dot)com> writes:
> I'm using libpq C Library. I prepared some query and trying to call it
> many times.
> But it success only at first time, and then fail with error:
> ... "another command is already in progress"
> [ PQsendQuery followed by just one PQgetResult ]
IIRC, you need to keep calling PQgetResult until it returns NULL
before the connection is considered cleared and ready for another query.
In this example you should get a NULL on the very next call, but
you didn't make that call.
regards, tom lane