Here is my example:
package Apache::Hits;
use strict;
use Apache::Constants qw(:common);
my ($sth_lock, $sth_upd, $sth_ins );
sub handler { my $r = shift; if ( $r->args() =~ /msg_id=(\d+)/o ) { $HTML::Mason::Commands::dbs ||= My::DB->new(1);
my$dbh = $HTML::Mason::Commands::dbs->{dbh}; $sth_lock ||= $dbh->prepare("LOCK TABLE hits IN SHARE ROW EXCLUSIVE
MODE"); $sth_upd ||= $dbh->prepare("UPDATE hits SET count=count+1,last_access=now() WHERE msg_id=?"); $sth_ins ||=
$dbh->prepare("INSERTINTO hits (msg_id,count) VALUES (?, 1)"); $dbh->{AutoCommit} = 0; my $success = 1; $success
&&=$sth_lock->execute(); $success &&= $sth_upd->execute( $1 ); $success &&= $sth_ins->execute( $1 ) if ( $success
eq'0E0'); my $result = ($success ? $dbh->commit : $dbh->rollback); unless ( $result ) { $r->log_error("Unable
toprocess transaction: ". $dbh->errstr ."\n"); } } return OK;
}
1;
__END__
On Thu, 24 Feb 2000, Zeugswetter Andreas SB wrote:
> Date: Thu, 24 Feb 2000 10:18:58 +0100
> From: Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at>
> To: "'kdebisschop@range.infoplease.com'" <kdebisschop@range.infoplease.com>
> Cc: "'hackers@postgresql.org'" <hackers@postgreSQL.org>
> Subject: AW: [GENERAL] Re: [HACKERS] TRANSACTIONS
>
> > ========================= example =========================
> >
> > $dbh->{AutoCommit} = 0;
> > $dbh->do("CREATE TABLE tmp (a int unique,b int)");
> > while (<>){
> > if (/([0-9]+) ([0-9]+)/) {
> > $rtv = $dbh->do("INSERT INTO tmp VALUES ($1,$2)");
> > if ($rtv) {$dbh->do("UPDATE tmp SET b=$2 where a=$1")};
> > }
> > }
> > $dbh->commit;
> > $dbh->disconnect;
> >
> > ========================= end ============================
>
> This is a very good example, and is unfortunately currently not possible in
> PostgreSQL. But I am sure Vadim is on his way to fix that :-)
>
> Andreas
>
> ************
>
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83