如何使用现有的ctp文件在mysql的下一行添加新数据？

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 ...!

May be you must create an object to each of them.

        $bill_1=new Bill;
        $bill_2=new Bill;
        $this->Bill->create();
        $bill_1->saveField('category',$a);
        $bill_1->saveField('subcategory',$b);
        $bill_2->saveField('category',$c);
        $bill_2->saveField('subcategory',$d);
        if($bill_1->save() && $bill_2->save()){
            $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'));*/

I don't know how your method save the data. I just want to say that you must create an object to create a row. CMIIW.

You need to build an array of key value pair then save it in your database table

$data = array (
    array(
        'a' => $_POST['category'],
        'b' => $_POST['subcategory']

    ),
    array(
        'a' => $_POST['category'],
        'b' => $_POST['subcategory'],
    ),
);

Then pass the array to insert query. The root of the problem is how your data is coming out from the $_POST. It should have been formatted and sent as an array of key value pairs. Hope this help.