Re: AW: [GENERAL] Re: [HACKERS] TRANSACTIONS
От | Karl DeBisschop |
---|---|
Тема | Re: AW: [GENERAL] Re: [HACKERS] TRANSACTIONS |
Дата | |
Msg-id | 200002241523.KAA02174@skillet.infoplease.com обсуждение исходный текст |
Ответ на | Re: AW: [GENERAL] Re: [HACKERS] TRANSACTIONS (Oleg Bartunov <oleg@sai.msu.su>) |
Список | 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("INSERT INTO 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 to process transaction: ". $dbh->errstr ."\n"); > } > } > return OK; >} > >1; >__END__ Maybe I'm missing something - I don't use the Apache module, nor the mason module, so it's difficult for me to decode this. But I looks to me like this commits or rolls back one statement at a time. What I want to be able to do is run a multi-statement transaction, and for each statement in the transaction try to fix it if an error is generated. If I cannot fix it, I want to roll back all of the previous statements in the transaction. If I can fix it, I want to clear the error status and continue on to the next statement in the transaction. Does your counter example do this in some way that I am not seeing? -- Karl DeBisschop <kdebisschop@alert.infoplease.com> 617.832.0332 (Fax: 617.956.2696) Information Please - your source for FREE online reference http://www.infoplease.com - Your Ultimate Fact Finder http://kids.infoplease.com - The Great Homework Helper Netsaint Plugins Development http://netsaintplug.sourceforge.net
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