php prepare stmt json type call

php prepare stmt json type call

function getComments($inPostID=null)
{
    $commentArray = array();
    $tempArray = array();

    if (!empty($inPostID))
    {
        //echo " Get comments for the post with the postID of ". $inPostID;
        $stmt = db::connect()->prepare("SELECT * FROM Comments WHERE postID = ? ORDER BY commentDate DESC");
        $stmt->bind_param('i', $inPostID);
        $stmt->execute();
        $stmt->bind_result($commentID, $postID, $userID, $commentDate, $commentContent);
        while($stmt->fetch())
        {
            $bindResults = array($commentID, $postID, $userID, $commentDate, $commentContent);
            array_push($tempArray, $bindResults);
        }
        $stmt->close();
        $total = count($tempArray);
        for($i = 0; $i < $total; $i++)
        {
            $thisComment = new ViewComment($tempArray[$i][0], $tempArray[$i][1], $tempArray[$i][2], $tempArray[$i][3], $tempArray[$i][4]);
            array_push($commentArray, $thisComment);
        }
    }
    return $commentArray;
} 

$conn = new mysqli(DB_HOST,DB_USERNAME,DB_PASSWORD, DB_NAME);

if($stmt = $conn->prepare('select * from users where u_id = ?'))
{
    $stmt->bind_param("s", $param);
    $stmt->execute();
    $stmt->bind_result($column1, $column2, $column3);

    while ($stmt->fetch()) {
        echo "Column 1: $column1\n";
        echo "Column 2: $column2\n";
        echo "Column 3: $column3\n";
    }

    $stmt->close();
}