my $citydata = $dbh->exec_select( "select city,state from mytable where city  = ?", $city );

 my @states = map {$_->{state}} @$citydata;
 my $statedata = join ' OR ', map { "state = ?" } @$citydata;

 my $codedata = $dbh->exec_select( "select code from othertable where (year=2014 and ($statedata)), @states );