我的代码有什么问题？我可以让它工作，但错误 Notice: Object of class mysqli_result could not be converted to int in C:\xampp\htdocs\PHP\index.php 第50行出现在上面。
真正的问题是如果我 if($check_email > 0){ 至 if($check_email_row > 0){ 我不能使错误消息“电子邮件已注册”显示在下面的电子邮件文本框和添加相同的现有电子邮件。

<?php

include("connection.php");

$name = $address = $email = $password = $cpassword = "";

$nameErr = $addressErr = $emailErr = $passwordErr = $cpasswordErr = "";

if($_SERVER["REQUEST_METHOD"] == "POST"){

if(empty($_POST["name"])){
        $nameErr = "Name is required!";
    }
    else{
        $name = $_POST["name"];
    }

if(empty($_POST["address"])){
        $addressErr = "address is required!";
    }
    else{
        $address = $_POST["address"];
    }
if(empty($_POST["email"])){
        $emailErr = "email is required!";
    }
    else{
        $email = $_POST["email"];

    }
if(empty($_POST["password"])){
        $passwordErr = "Password is required!";
    }
    else{
        $password = $_POST["password"];
    }
if(empty($_POST["cpassword"])){
        $cpasswordErr = "Confirm Password is required!";
    }
    else{
        $cpassword = $_POST["cpassword"];
    }

if($name && $address && $email && $password && $cpassword){

    $check_email = mysqli_query($connections,"SELECT email FROM mytbl WHERE email='$email'");

    $check_email_row = mysqli_num_rows($check_email);

    if($check_email > 0){

        $emailErr = "Email is already registered!";

    }else{

        $query = mysqli_query($connections, "INSERT INTO mytbl (name,address,email,password,account_type)
        VALUES ('$name','$address','$email','$cpassword','2')");

        echo "<script language='javascript'>alert('New Record Has Been Added!')</script>";
        echo "<script>window.location.href='index.php';</script>";

    }

    }
}
?>

<style>
 .error{
     color:red;
 }
 </style>

 <?php include("nav.php");?>

 <br>
 <br>

<form method="POST" action="<?php htmlspecialchars("PHP_SELF"); ?>">

Name:<input type="text" name="name" value="<?php echo $name; ?>"> <br>
<span class="error"><?php echo $nameErr; ?></span><br>

Address:<input type="text" name="address" value="<?php echo $address; ?>"> <br>
<span class="error"><?php echo $addressErr; ?></span><br>

Email:<input type="text" name="email" value="<?php echo $email; ?>"> <br>
<span class="error"><?php echo $emailErr; ?></span><br>

Password:<input type="password" name="password" value="<?php echo $password; ?>"> <br>
<span class="error"><?php echo $passwordErr; ?></span><br>

Confirm Password:<input type="password" name="cpassword" value="<?php echo $cpassword; ?>"> <br>
<span class="error"><?php echo $cpasswordErr; ?></span><br>

<input type="submit" value="Submit"> 

</form>

<hr>

<?php

    $view_query = mysqli_query($connections, "SELECT * FROM mytbl");

    echo "<table border='1' width='50%'>";
    echo "<tr>
        <td>Name</td>
        <td>Address</td>
        <td>Email</td>

        <td>Option</td>
        </tr>";

    while($row = mysqli_fetch_assoc($view_query)){
    $user_id = $row["id"];

    $db_name = $row["name"];
    $db_address = $row["address"];
    $db_email = $row["email"];

    echo "<tr>
        <td>$db_name</td>
        <td>$db_address</td>
        <td>$db_email</td>

        <td>
        <a href='Edit.php?id=$user_id'>Update</a>
        &nbsp;
        <a href='ConfirmDelete.php?id=$user_id'>Delete</a>
        </td>
        </tr>";

    }
    echo"</table>";

?>

<hr>
<?php

$names = array("ian","Joshua","vinoya");

foreach($names as $display_names) {

    echo $display_names . "<br>";

}

?>