Handy Hack:Perl DBI count rows returned from select statment

gistfile1.pl

#From http://alecthegeek.wordpress.com/2007/02/09/handy-hackperl-dbi-count-rows-returned-from-select-statment/
#In theory it’s a bad thing to assume a select will return a single scalar value instead of multiple attributes and rows, however with a count #clause we should be pretty safe. N.B. using the $dbh->rows() function or similar is not correct on a select statement.
my $rowCount = $dbh->selectrow_array(
                  qq{
                     SELECT count(*)
                     FROM my_table
                     WHERE attr1 = ?
                  }, undef, $myValue);