pdostatement::fetch-k8凯发旗舰

function readdataforwards($dbh) {
   $sql = 'select hand, won, bet from mynumbers order by bet';
   $stmt = $dbh->prepare($sql, array(pdo::attr_cursor => pdo::cursor_scroll));
   $stmt->execute();
   while ($row = $stmt->fetch(pdo::fetch_num, pdo::fetch_ori_next)) {
       $data = $row[0] . "\t" . $row[1] . "\t" . $row[2] . "\n";
       print $data;
   }
}
function readdatabackwards($dbh) {
   $sql = 'select hand, won, bet from mynumbers order by bet';
   $stmt = $dbh->prepare($sql, array(pdo::attr_cursor => pdo::cursor_scroll));
   $stmt->execute();
   $row = $stmt->fetch(pdo::fetch_num, pdo::fetch_ori_last);
   do {
       $data = $row[0] . "\t" . $row[1] . "\t" . $row[2] . "\n";
       print $data;
   } while ($row = $stmt->fetch(pdo::fetch_num, pdo::fetch_ori_prior));
}

print "reading forwards:\n";
readdataforwards($conn);

print "reading backwards:\n";
readdatabackwards($conn);
?>  

以上例程会输出：

reading forwards:
21    10    5
16    0     5
19    20    10
reading backwards:
19    20    10
16    0     5
21    10    5

example #3 构造顺序