$dbh->do() is for very simple cases (like SELECT COUNT(*) FROM some_table). You don't have a simple case.

actually, $dbh->do() won't work for that either. from the documentation:

Returns the number of rows affected or "undef" on error. A return value of "-1" means the number of rows is not known, not applicable, or not available.

This method is typically most useful for non-"SELECT" statements that either cannot be prepared in advance (due to a limitation of the driver) or do not need to be executed repeatedly. It should not be used for "SELECT" statements because it does not return a statement handle (so you can't fetch any data).

anders pearson