On Tue, 2011-08-30 at 19:29 +0100, Dave Page wrote:
> On Tue, Aug 30, 2011 at 6:15 PM, Guillaume Lelarge
> <guillaume(at)lelarge(dot)info> wrote:
> >> libpq doesn't support multiple resultsets in a single query unfortunately.
> > As a matter of fact, it does (see
> > http://pgolub.wordpress.com/2009/11/17/script-slicing-by-pgmdd/), and I
> > really want pgAdmin to use this. Still need to find a good UI and some
> > time to work on it :)
> Err, no it doesn't. The blog you've referenced describes how PgMDD
> takes the PostgreSQL 8.3 parser and uses it to pre-parse scripts into
> individual statements on the client, which it then executes
> individually. That's similar to what's being asked for here, but has
> the rather nasty limitation of not understanding PG 8.4+'s grammar.
> Libpq itself only supports a single resultset for multi-part
> statements. Even in 9.1, the docs say:
> The command string can include multiple SQL commands (separated by
> semicolons). Multiple queries sent in a single PQexec call are
> processed in a single transaction, unless there are explicit
> BEGIN/COMMIT commands included in the query string to divide it into
> multiple transactions. Note however that the returned PGresult
> structure describes only the result of the last command executed from
> the string. Should one of the commands fail, processing of the string
> stops with it and the returned PGresult describes the error condition.
> In other words, only the last resultset is accessible.
You're right for PQexec. And wrong for PQsendQuery, which is the one we
use on the query tool.
And to quote the fine manual :)
After successfully calling PQsendQuery, call PQgetResult one or more
times to obtain the results. PQsendQuery cannot be called again (on the
same connection) until PQgetResult has returned a null pointer,
indicating that the command is done.
In response to
pgadmin-support by date
|Next:||From: Dave Page||Date: 2011-08-30 19:42:18|
|Subject: Re: feature request|
|Previous:||From: Strauch, Sheldon||Date: 2011-08-30 19:18:17|
|Subject: pgAdmin3 quits unexpectedly on Mac OS/X|