Controller

```
if ($this->request->is('post')) {
    $a = $_POST['category'];
    $b = $_POST['subcategory'];
    $c = $_POST['category1'];
    $d = $_POST['subcategory1'];
    // i have checked whether values are comming to controller r not

    echo $a;

    echo $b;

    echo $c;

    echo $d;
    //They are comming 

    // I have category and subcategory columns in my databse

    // I want to store $a and $b in one row ,$c and $d values in the next row of my database . 

    // I have written like this

    $this->Bill->create();
    if ($this->Bill->save($this->request->data)) {
        $this->Bill->saveField('category',$a);
        $this->Bill->saveField('subcategory',$b);
        $this->Bill->saveField('category',$c);
        $this->Bill->saveField('subcategory',$d);
            $this->Session->setFlash(__('The Bill has been saved'));
            return $this->redirect(array('controller' => 'Bills','action' => 'view'));
    }
    $this->Session->setFlash(__('The bill could not be saved'));*/
}
// but $c and $d  values are only storing  in row.

```

How to store $a and $b in one row ,$c and $d values in the next row of my database ?

please help me ...!