Untested Pseudocode.. (Assuming you use DBI )

  # Assumes DBI RaiseError is set ...
  my $sth = $dbh->prepare ("SELECT ID from $tbl where ID=?");

  for my $id (1..10_000){
      $sth->execute ($id);
      next if $sth->fetchrow_arrayref; 
      # This ID ($id)  was absent
      # Generate web page here...
  }
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