Saving Multiple Select in input

Question

I have model for

• user(id,name)
• section(id,name)
• section_users(id,user_id,section_id)

The admin adds all the users and sections

Answer 1

As already mentioned, this is exaplained in the docs, please read them, and in case you don't understand them (which would be understandable as the HABTM section is a little confusing and requires some trial & error), tell us what exactly you are having problems with.

http://book.cakephp.org/2.0/en/models/saving-your-data.html#saving-related-model-data-habtm

Based on the examples shown, the format for saving multiple X to Y should be

Array
    (
        [Section] => Array
            (
                [id] => 1
            )
        [User] => Array
            (
                [User] => Array(3, 4)
            )
    )

The corresponding form could look like this:

Form->create('User'); ?>
    Form->input('Section.id'); ?>
    Form->input('User', array('multiple' => 'checkbox')); ?>
Form->end('Add Users'); ?>

And the data would be saved via the Section model, that way its modified column is being updated properly.

public function addUsersToSection($id) {
    // ...
    if($this->request->is('post')) {
        if($this->Section->save($this->request->data)) {
            // ...
        } else {
            // ...
        }
    } else {
        $options = array(
            'conditions' => array(
                'Section.' . $this->Section->primaryKey => $id
            )
        );
        $this->request->data = $this->Section->find('first', $options);
    }

    $users = $this->Section->User->find('list');
    $this->set(compact('users'));
}

Another way would be to restructure the array as shown by Vinay Aggarwal, that works fine, the only difference is that it requires saving through the join model, and consequently it doesn't update the Section models modified column.