use DBI;

my $dbh = DBI->connect("DBI:mysql:database=www;host=myhost.domain.com:3306;user=auser;password=apwd",
{RaiseError => 1, PrintError => 0});

my $sql = 'select wrong_col, correct_col from table limit 10';

my $hash_ref;

print "Trying HandleError (with RaiseError on):\n";
$hashref = $dbh->selectall_hashref($sql, 'filename', 
	{RaiseError => 1, PrintError => 1, HandleError => \&handle_error()}); 

print "Trying RaiseError and eval:\n";
eval{					
	$hashref = $dbh->selectall_hashref($sql, 'filename', 
	{RaiseError => 1, PrintError => 0}); 
};
if ($@) {
		print "\tEval found: $@\n";
}

my $sth = $dbh->prepare($sql);

print "Trying Errstr:\n";
$sth->execute();
if ($dbh->errstr) {
	print "\tErrstr: " .$dbh->errstr . "\n";
}

sub handle_error { #
	my $error = shift;
	print "\tSub 'handle_error': $error\n";
	print "\tEnd sub\n";
}