为什么会出现“致命错误：在非对象上调用成员函数fetch_assoc（）”？

Question

I'm working in this project that is an Android login app. It fetches data from an online server.

The registration works and the database gets updated but the login does not work. We are using JSON to parse data from the server to the app.

Here is my PHP code:

public function getUserByEmailAndPassword($email, $password) {

    $stmt = $this->conn->prepare("SELECT * FROM user_info WHERE email = ?");

    $stmt->bind_param("s", $email);

    if ($stmt->execute()) {
        $user = $stmt->bind_result()->fetch_assoc();
        $stmt->close();
        return $user;
    } 
    else {
        return NULL;
    }
}

The error I'm getting is the following:

Fatal error: Call to a member function fetch_assoc() on a non-object.

Answer 1

bind_result() is not the method you want here. That method (which returns a boolean, by the way) lets you assign variables to the columns returned in your query. Your query uses SELECT * , so you cannot use bind_result() .

What you want is to use get_result() . This requires the mysqlnd driver to be installed.

$user = $stmt->get_result()->fetch_assoc();