Or a slightly different syntax: 
my ($field1, $field2, $field3) = (undef, undef, undef);
my $sth = $dbh->prepare('select * from table');
$sth->execute;
if ($sth->rows > 0) {
    $sth->bind_columns(\($field1, $field2, $field3));
    $sth->fetch;
}
$sth->finish;
for ($field1, $field2, $field3) { $_ ||= '' }

[download]
When dealing with failures caused by duplicate values (due to a constraint) I just check like this: 
    $dbh->do('insert into blah (?, ?, ?)', undef, $x, $y, $z);
    if ($dbh->err) {
        if ($dbh->err == 1062) {
            # duplicate
        } else {
            # some other problem
        }
    }

[download]
1062 happens to be the error code for MySQL.

Look at $DBI::lasth->{Statement} which has the last SQL statement you tried to execute which is quite handy in a debug subroutine.

In reply to Re: Handling Null or Undef values in DBI (and things of those nature)... by gav^
in thread Handling Null or Undef values in DBI (and things of those nature)... by data67

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