PHP를 사용하여 WeChat 애플릿의 작업 통계 기능을 개발하는 방법은 무엇입니까?

<button open-type="getUserInfo" bindgetuserinfo="onGetUserInfo">登录</button>

onGetUserInfo: function (res) {
  if (res.detail.userInfo) {
    wx.login({
      success: function (loginRes) {
        if (loginRes.code) {
          wx.request({
            url: 'https://api.weixin.qq.com/sns/jscode2session',
            data: {
              appid: '小程序的AppID',
              secret: '小程序的AppSecret',
              js_code: loginRes.code,
              grant_type: 'authorization_code'
            },
            success: function (res) {
              var openid = res.data.openid;
              // 将openid保存到本地或发送到后台服务器
            }
          });
        }
      }
    });
  }
}

<?php
$openid = $_POST['openid']; // 接收前端传递的openid参数

// 将openid保存到数据库
$servername = "localhost";
$username = "用户名";
$password = "密码";
$dbname = "数据库名";

$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
  die("连接失败: " . $conn->connect_error);
}

$sql = "INSERT INTO users (openid) VALUES ('$openid')";
if ($conn->query($sql) === TRUE) {
  echo "保存成功";
} else {
  echo "Error: " . $sql . "<br>" . $conn->error;
}

$conn->close();
?>

<?php
$openid = $_POST['openid']; // 接收前端传递的openid参数

// 查询用户的任务
$servername = "localhost";
$username = "用户名";
$password = "密码";
$dbname = "数据库名";

$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
  die("连接失败: " . $conn->connect_error);
}

$sql = "SELECT COUNT(*) as count FROM tasks WHERE openid = '$openid'";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
  while($row = $result->fetch_assoc()) {
    $count = $row["count"];
    echo "用户的任务数量：" . $count;
  }
} else {
  echo "用户没有任务";
}

$conn->close();
?>