Php 用户类在数据库中不将重复电子邮件返回为false

我创建了一个user类，它验证通过表单传递的数据，然后更新数据库表users。我想添加额外的功能，例如检查表中是否存在用户名和电子邮件，我已经从stackoverflow的成员那里获得了一些帮助，以便开始构建此功能，但是下面的代码仍然允许将重复的电子邮件插入数据库，我没有收到任何sql错误消息，只收到一条成功消息，如下所示“插入1行”。显然，我希望收到错误消息“email exists”

任何帮助都会有帮助

public function insert() {

$result = $this->mysqli->prepare("SELECT COUNT(*) FROM users WHERE email=?");
$result->bind_param("s", $_POST['email']);
$result->execute();
$result->bind_result($email_count);
$result->close();   

if ($email_count > 0) {
echo "email exisits!";
} else {
//escape the POST data for added protection
    $username = isset($_POST['username']) ? $this->mysqli->real_escape_string($_POST['username']) : '';
    $cryptedPassword = crypt($_POST['password']);
    $password = $this->mysqli->real_escape_string($cryptedPassword);
    $name = isset($_POST['name']) ? $this->mysqli->real_escape_string($_POST['name']) : '';
    $email = isset($_POST['email']) ? $this->mysqli->real_escape_string($_POST['email']) : '';
    $stmt = $this->mysqli->prepare("INSERT INTO users (username, password, name, email) VALUES (?, ?, ?, ?)");
    //var_dump($this->mysqli->error);
    $stmt->bind_param('ssss', $username, $password, $name, $email); // bind strings to the paramater
    /* execute prepared statement */
    $stmt->execute();
    printf("%d Row inserted.\n", $stmt->affected_rows);
    /* close statement and connection */
    $stmt->close();
                } // end email_count and insert to table
            } // end function

我使用了下面附带的ajax代码，它对我很有用。。。。 如果有用的话，试试看

ajax代码-----------------

---

之后您需要调用

fetch

：

$result->bind_result($email_count);
$result->close(); 
$result->fetch();//fecth
$result->close(); 
//then


if ($email_count > 0) {
echo "email exisits!";
}

注意，对于准备好的语句，不需要使用

real\u escape\u string

@RequestMapping(value="checkAvailability",method = RequestMethod.GET)
public @ResponseBody String getAvailability(@RequestParam("username") String username) {
    System.out.println("username is"+username);
    boolean status=userService.available(username);

    if(status)
    {
    return "available";
    }
    else 
    return "username already exists";
}

$result->bind_result($email_count);
$result->close(); 
$result->fetch();//fecth
$result->close(); 
//then


if ($email_count > 0) {
echo "email exisits!";
}