Updating array item from parent class in child class - php

Question

I'm fairly new to OOP in PHP. I'm trying to update the value of an item in an array that is generated by a loop in its parent class. In my code the class DatabaseObject creates an attributes array with all of the table field name and value pairs. The contents of the array are used to create a SQL query to write to the database. The issue that I'm trying to resolve is that I need to update the attributes['hashed_password'] item with an encrypted password from the child User class. I'm not quite sure how I would update that array item so that the hashed password is submitted to the database instead of what came through a form submission.
class DatabaseObject {
public function create(){
global $db;
static::$attributes = [];
foreach (static::$db_fields as $field) {
if(property_exists($this, $field)){
$attributes[$field] = $this->$field;
}
}
$sql = "INSERT INTO " . static::$table_name . " (";
$sql .= join(", ", array_keys($attributes));
$sql .= ") VALUES ('";
$sql .= join("', '", array_values($attributes));
$sql .= "')";
$result = mysqli_query($db, $sql)
}
}
class User extends DatabaseObject {
protected static $table_name="users";
protected static $db_fields = array("user_id", "username", "hashed_password", "email");
public $user_id;
public $username;
public $hashed_password;
public $email;
self::attributes['hashed_password'] = password_hash($this->attributes['hashed_password'], PASSWORD_BCRYPT);
}
Any help would be appreciated.

Answer 1

The solution that worked for me was just to override the create function in the User object and manually update the array with the hashed password, so the new User object became:
class User extends DatabaseObject {
public function create(){
global $db;
static::$attributes = [];
foreach (static::$db_fields as $field) {
if(property_exists($this, $field)){
$attributes[$field] = $this->$field;
}
}
$attributes['hashed_password'] = password_hash($attributes['hashed_password'], PASSWORD_BCRYPT);
$sql = "INSERT INTO " . static::$table_name . " (";
$sql .= join(", ", array_keys($attributes));
$sql .= ") VALUES ('";
$sql .= join("', '", array_values($attributes));
$sql .= "')";
$result = mysqli_query($db, $sql)
}
}
}
Not sure if that's the most efficient way to do it, but it worked.