pdo, insert php object to database

Question

I can't find an answer to this question.

I want to save a PHP object into a MySQL database. Example:

class user{
  private $id, $email, $pw, $first, $last, $group,.....;
 // getters and setters    
}

class someclass{

public function someFunction(){
  $pdo = new PDO(...);
  $objUser = new user();
  $objUser->setEmail(....);
  $objUser->setFirst(....);
  //bla bla bla

 // and I want to save this user object to the DB with something like:
  $pdo->insert($objUser); //in this case db table equals to class name
  //instead of building/writing query manually. 
  //for mysql_query I have made a class for building queries for insert, update and delete 
  //but mysq_query is old and deprecated
}

}

The main reason I am asking for this is because I don't want to write something that can exists by default.

Thank you.

Answer 1

I would probably implement insert, update and delete methods in the user class, rather than making it a feature of the database class to interpret the object being given to it.

There is not a built-in method of doing this in PHP or the mysql PDO classes, but some frameworks implement an ORM (object relational mapping) that allow you to specify easily in your object classes how they interact with the database. ( Laravel framework ORM docs )

Here's a very basic way you could implement it.

class ORM {
    public function insert($pdo) {
        // Get object name
        // Get object properties
        // Check if database table exists with object name
        // Generate and run a query to insert a record into that table
        // using the property names and values
    }
    public function update($pdo) {
        // Like insert, but update
    }
    public function delete($pdo) {
        // Etc...
    }
}

class user extends ORM {
    private $id, $email, $pw, $first, $last, $group,.....;
    // getters and setters    
}

class someclass{
    public function someFunction(){
      $pdo = new PDO(...);
      $objUser = new user();
      $objUser->setEmail(....);
      $objUser->setFirst(....);
      //bla bla bla

      $objUser->insert($pdo);
    }
}

Answer 2

You could extend your model classes with a Model class.

Use property names that are the same as MySQL table names.

In this class you can create a saveToDb($tableName) (or omit the tableName if you define it as a class property) method that:

1. Gets the columns from the MySQL table using query

   "DESCRIBE tablename"

2. Gets the properties from the Class instance:

    get_object_vars($this)

3. Calculate the intersection from 1. and 2. (remove id column from 1. depending on your setup and DB model).

Now for matching columns you can insert (or update) MySQL table. You can create the query dynamically from this (use PDO if your values have user generated content).

If you use extend Model you still have to freedom to override if for some reason in some class you need some extra processing before saving.