sub Fetch_w_callback{ # Main DBI retrieval mechanism---- my ($sql, $callback) = @_; my $state = $_[2] ||= {}; # ** This THIRD param is CALL-by-ref ** $debug{SQL} = $sql; (my $sth= $state->{STH} = $dbh->prepare($sql))->execute(); $state->{ROW} = $state->{QUIT} = 0; while (my $row = $sth->fetchrow_hashref()){ $debug{ROW} = $state->{ROW}++; #last if ($callback->($row,$state) || 0) < 0; # Return negative to quit $callback->($row,$state); last if $state->{QUIT}; # Call-ee asked us to stop. } $sth->finish; } #### my $sql= "SELECT blah blah...."; Fetch_w_callback( "COPY ($sql) TO STDOUT CSV HEADER", # Let pg do csv work sub { my ($row,$state) = @_; print $row,"\n"; ##$fieldnames ||= $state->{STH}->{NAME} || [keys %$row]; ##if ($state->{ROW} ==1 ){ ## print $state->{HEADER} = ## join(",",@$fieldnames, "SOURCE=\@$ENV{HOSTNAME}" ## . " on " . scalar(localtime(time))) ."\n"; # Header row ##} ## ##print join(",", map{defined $_?$_:""}@$row{@$fieldnames}) ."\n"; return 0; }, $state );