php正在连接数据库但未插入数据

Question

我的php代码未插入任何数据，也未在 series: [ { type: 'pie', id: 'pie', radius: '30%', center: ['50%', '25%'], label: { formatter: '{b}: {@2019-12-12} ({d}%)' }, encode: { itemName: 'date', value: '2019-12-12', tooltip: '2019-12-12' } } ] 中显示错误

有人可以帮助我吗？

这是我的html代码：-

$num= mysqli_num_rows($result);

这是我的php代码

<form action="registrationDB.php" method="post">
    <input type="text" name="full_Name" placeholder="Your Full Name" required="" class="form-control"><br>
    <input type="text" name="user_name" placeholder="Username" required="" class="form-control"><br>
    <input type="tel" name="whatsapp_Number" placeholder="Whatsapp Number" minlength="10" maxlength="10" required="" class="form-control"><br>
    <input type="password" name="pass" placeholder="Password" required="" class="form-control"><br>
    <input type="password" name="password_Conf" placeholder="Confirm Password" required="" class="form-control"><br>
    <input type="tel" name="referral_Code"  placeholder="Referral Code(Optional)" minlength="10" maxlength="10" class="form-control"><br>
    <div class="custom-control custom-checkbox mb-3">
        <input type="checkbox" class="custom-control-input" id="agreeCheckBox" required>
        <label class="custom-control-label" for="agreeCheckBox" style="color: white;">something.</label>
    </div>
    <input type="submit" value="Register" class="btn btn-success">
</form>