Re: AW: [GENERAL] Re: [HACKERS] TRANSACTIONS - Mailing list pgsql-hackers

From Oleg Bartunov
Subject Re: AW: [GENERAL] Re: [HACKERS] TRANSACTIONS
Date
Msg-id Pine.GSO.3.96.SK.1000224134525.22930M-100000@ra
Whole thread Raw
In response to AW: [GENERAL] Re: [HACKERS] TRANSACTIONS  (Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at>)
Responses Re: AW: [GENERAL] Re: [HACKERS] TRANSACTIONS
List pgsql-hackers
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



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