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：

<?php

header('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)){&nbsp; &nbsp; $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)){&nbsp; &nbsp; $points = $row['points'];}