MYSQL 获取列值并在PHP中显示

Question

我有个问题我想回显“点”列的值我尝试过，但没有用：$stmt = $mysqli->prepare("SELECT points FROM member_profile WHERE user_id = '$firstName'");$stmt->execute();$array = [];foreach ($stmt->get_result() as $row){    $array[] = $row['points'];}print_r($array);这是我当前的代码：<?phpheader('Content-Type: text/html; charset=Windows-1250');    session_start();$firstName = $_SESSION['firstname'];$servername = "db.xxxx.gsp-europe.net";$username = "xxxxxxxxxxxxx";$password = "xxxxxxxxxxxxxx";$dbname = "xxxxxxxx";/// Create connection$conn = new mysqli($servername, $username, $password, $dbname);// Check connection   if ($conn->connect_error) {    die("Connection failed: " . $conn->connect_error);} // check if the user exist$check = "SELECT * FROM `member_profile` WHERE user_id = '$firstName'";$result = mysqli_query($conn,$check) or die(mysqli_error($conn));        $rows = mysqli_num_rows($result);        //if exist increse points with 1        if($rows>=1){$sql = "UPDATE `member_profile` SET points = points + 1 WHERE user_id = '$firstName'";   if ($conn->query($sql) === TRUE) {    echo "Thingz created successfully";} else {    echo "Error doing sum thingz: " . $conn->error;}        }        //if don't exist create user with points 0        if($rows==0)        {            $query = "INSERT into `member_profile` (user_id, points) VALUES ( '$firstName' ,'0')";            $result = mysqli_query($conn,$query)or die(mysqli_error($conn));$conn->close();        }?>简而言之，我需要什么：在文件的末尾，将是一个“回声”，它将显示带有标识符“user_id”的“点”列的当前值。就这样

Answer 1

您正在获取结果，但未获取数据。

$stmt->get_result()返回一个结果集 -> mysqli_result并且要处理这个，您需要从该结果调用方法fetch_array()。

将您的代码更改为：

$results = $stmt->get_result();

while ($row = $result->fetch_array(MYSQLI_ASSOC))

{

    $array[] = $row['points'];

}

如果您只想要 1 个结果而不使用数组，请不要使用数组（是的，是的）。

$results = $stmt->get_result();

while ($row = $result->fetch_array(MYSQLI_ASSOC))

{

    $points = $row['points'];

}