在PHP中从数组创建json

Question

I have this little sql code:

try {
        $stmt = $conn->prepare("SELECT APPID FROM COMMENTROOM WHERE BADGEID=? GROUP BY APPID");
        $stmt->execute(array($badgeID));
            while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
                $row2[$i][0] = $row['APPID'];
                $i++;
            }
        } catch(PDOException $e) {
            echo 'ERROR: ' . $e->getMessage();
            $server_dir = $_SERVER['HTTP_HOST'] . rtrim(dirname($_SERVER['PHP_SELF']), '/\\');
            header('Location: http://' . $server_dir);
            exit();
    }

When I now print out the result with print(json_encode($row2)); I get the following:

[["0000000021"],["0000000037"],["0000000038"],["0000000039"],["0000000128"],["0000000130"]]

Since I already have this data I don't need to query the database. But I still need to forward it in the same format to my Java app. When I use

$output[] = json_encode($row2);
print(json_encode($output));

I get a different output:

["[[\"0000000021\"],[\"0000000037\"],[\"0000000038\"],[\"0000000039\"],[\"0000000128\"],[\"0000000130\"]]"]

I checked a few stackoverflow questions but I didn't find any that addresses the same problem.

Answer 1

You are json encoding it twice

$output[] = json_encode($row2);
print(json_encode($output));

Just do it once:

$output[] = $row2;
print(json_encode($output));