如何使用bind_result和fetch将值分配给变量？

Question

I want to get values from my database and assign them to a variable. This is my code.

    $stmt = $this->conn->prepare("SELECT ngno, email, encrypted_password, name, user_type FROM `guide` WHERE email = ?");
    $stmt->bind_param("s", $email);

    if ($stmt->execute()) {
        $stmt->bind_result($ngno, $email, $encrypted_password, $name, $user_type);
        $user = $stmt->fetch();
        $stmt->close();

        if($encrypted_password == $password){
            return $user;
        }
    } else {
        return NULL;
    }

i need to assign the values from my table to the variable $user and return it to my login.php file.

$user = $db->getUserByEmailAndPassword($email, $password);

if ($user != false) {
    // use is found
    $response["error"] = FALSE;
    $response["ngno"] = $user["ngno"];
    $response["user"]["email"] = $user["email"];
    $response["user"]["name"] = $user["name"];  
    $response["user"]["user_type"] = $user["user_type"];
    echo json_encode($response);
} else {
    // user is not found with the credentials
    $response["error"] = TRUE;
    $response["error_msg"] = "Login credentials are wrong. Please try again!";
    echo json_encode($response);
}

my code doesnt seem to assign values into the $user variable. what am i doing wrong?

Answer 1

Since I cannot put a comment, have you tried:

var_dump($user);

If it returns NULL, check your method getUserByEmailAndPassword, especially this line:

$encrypted_password == $password

Since your are comparing your $encrypted_password to the $password variable, are you sure that the $password variable you are comparing to is also the encrypted (should be hashed) password? Will be updating this answer once you respond.

Answer 2

The problem is because of the following statement in getUserByEmailAndPassword() method,

$user = $stmt->fetch();

fetch() method fetches results from a prepared statement into the bound variables, and the method actually returns true or false .

Here's the reference:

• mysqli_stmt::fetch

Instead create an array, say $user and push those bound variable values into the array. And finally return the array from the method.

So your getUserByEmailAndPassword() method should be like this:

public  function getUserByEmailAndPassword($email, $password){
    $stmt = $this->conn->prepare("SELECT ngno, email, encrypted_password, name, user_type FROM `guide` WHERE email = ? LIMIT 1");
    $stmt->bind_param("s", $email);

    if ($stmt->execute()) {
        $stmt->bind_result($ngno, $email, $encrypted_password, $name, $user_type);
        $user = array();
        if($stmt->fetch()){
            if($encrypted_password == $password){
                $user['ngno'] = $ngno;
                $user['email'] = $email;
                $user['name'] = $name;
                $user['user_type'] = $user_type;

                $stmt->close();
                return $user;
            }else{
                return false;
            }

        }else{
            return false;
        }
    } else {
        return false;
    }
}