ichimunki has the answer - i just wanted to point out a couple of style issues:

1. don't be afraid to use whitespace:

$header_id = $dbh->prepare("
  SELECT id 
  FROM press_release
  WHERE header = ?
");
[download]

Makes the SQL much much more readable - but what about the question mark? That's #2:

2. Use bind variables instead of interpolated statements. If this statement is to be executed again and again, using bind variables will increase performance. So, how do you tell DBI what the value of the question mark is? Inside the execute function:

$header_id->execute($header);
[download]

Check out Programming the Perl DBI for more DBI goodness.

jeffa