[Deprecated] DMZ 1.5.3 (DataMapper OverZealous Edition)

[eluser]OverZealous[/eluser]
FYI: I charge $100/hour for consultation ;-P

There are a lot of different ways to handle it. Most likely, it will involve having a single table that looks something like this:

Code:

"
id | name        | job         | supervisor_id
---+-------------+-------------+----------------
1  | John Smith  | CEO         | NULL
2  | Susan Jones | VP of Finan…| 1
3  | Joe Bloe    | Employee    | 2
"

In this example, there is only one supervisor/boss per employee. If you want multiple bosses (e.g.: like Office Space), that requires a dedicated table for tracking those relationships.

My DataMapper model might look like this:

Code:

class Employee extends DataMapper {
    $has_one = array(
        // This employee's supervisor
        'supervisor' => array(
            'class' => 'employee'
        )
        // This could also be specified in shorthand as
        // 'supervisor' => 'employee', but I don't recommend that
    );

    $has_many = array(
        // This employee's sub-employees.
        // note that, since 'class' is the same as the related field,
        // you don't need to specify it.
        'employee' => array(
            'other_field' => 'supervisor'
        )
    );
}

This relationship is a little different, because I wanted to have $boss->employee list all of the employees for the Employee $boss. (I needed to show this, so I'm sorry if it is confusing.) Because of this, you'll notice there is less fields specified.

Now let's add a new employee, and insert her between Susan and Joe (we always can use more middle managers, right? ;-) ):

Code:

$jane = new Employee();
$jane->name = "Jane Doe";
$jane->job = "Middle Manager";

$susan = new Employee();
$susan->get_by_id(2);

$joe = new Employee();
$joe->get_by_id(3);

// Save Jane, AND the relationships, all at once.
$jane->save(array(
    'supervisor' => $susan,
    'employee' => $joe
));
// note that $jane will overwrite $susan for $joe, so we don't need to delete that relationship!

Now, to get the supervisor or employees of a person, it's very simple:

Code:

$susan = $jane->supervisor->get();
$employees = $jane->employee->get();

If you want to see if you are at the head honcho, you could try:

Code:

$head_honcho = ! $person->supervisor->get()->exists();

One final example. Say you didn't want to use Employee->employee, you might have something like this:

Code:

class Employee extends DataMapper {
    $has_one = array(
        // This employee's supervisor
        'supervisor' => array(
            'class' => 'employee',
            'other_field' => 'subordinate'
        )
    );

    $has_many = array(
        // This employee's subordinates.
        'subordinate' => array(
            'class' => 'employee',
            'other_field' => 'supervisor'
        )
    );
}

Everything else stays the same!