Getting data from table on input_post codeigniter - php

Question

So I'm creating an application for clients to fill in an order to calculate the price. The client has to fill in a form, the form will be posted to a table in MySQL. When the order is complete the client gets an overview of his order with the calculated price. I'm having trouble with storing a variable (from tblPanel_Prices) which is related with a variable in tblPaneltypes. So after filling in the form data from column tblPaneltypes and tblPanel_Prices should be stored together in another table. Both tables (types and prices) are related.
The client has to select a type of panel. These types are stored in the table (tblPaneltypes). Every panel has a certain price-categorie (field price_id) which is needed to calculate the price. The prices of the paneltypes are stored in another table (tblPanel_Prices). There is a relation between the tblPaneltypes and tblPanel_Prices (both integer)
So the client fills in the form and selects a certain type of panel, this gets posted (controller) to the table with the function: this->input->post('paneltype').
After this I want to calculate the surface of the panel and make select the right price-category on the field price-id.
So in the form there is a type of panel choosen by the client. This already goes to my table, but I also want to pass the price_id tag in the form.
Then, I would like to get the price_id tag from the table tblPaneltypes to link this with the price_id tag in tblPanel_Prices. The value of the price_id isn't important for the client, so no need to select or show this value. I just need it to calculate the price of the panel (which depends on the type of panel filled in by the client)
Thanks in advance!
Store function in controller
public function store()
{
$this->load->model("orders/panels/Panels");
$this->form_validation->set_rules('amount', 'aantal', 'numeric|required|max_length[2]');
$this->form_validation->set_rules('dwidth', 'paneelbreedte', 'numeric|callback_check_width');
$this->form_validation->set_rules('dheight', 'paneelhoogte', 'numeric|callback_check_height');
$this->form_validation->set_rules('paneltype', 'paneeltype', 'required');
$this->form_validation->set_rules('ral_code', 'ral kleur', 'callback_check_double');
if ($this->auth()) {
if ($this->form_validation->run() == FALSE) {
$this->read_panel();
} else {
$panel = $this->Panels->create__entry(
$this->input->post('order_id'),
$this->input->post('amount'),
$this->input->post('dwidth'),
$this->input->post('dheight'),
$this->input->post('paneltype'),
$this->input->post('panelcategory'),
$this->input->post('color'),
$this->input->post('othercolor'),
$this->input->post('tubes'),
$this->input->post('colorswatch'),
$this->input->post('structurepaint'),
$this->input->post('uv'),
$this->input->post('window'),
$this->input->post('paintwindow'),
$this->input->post('windowsetup'),
$this->input->post('glastype'),
$this->input->post('door')
);
redirect("rail/read_rail?order=" . $this->input->post('order_id'));
}
} else {
login();
}
create__entry in model: at this moment I'm filling in the panelcategory manually in the model in. In the future it should filled in automaticly.
function create__entry($order_id, $amount, $dwidth,
$dheight, $paneltype, $panelcategory, $color,
$othercolor, $tubes,
$colorswatch, $structurepaint,
$uv, $windowtype, $paintwindow,
$windowsetup, $glastype, $door)
{
$this->order_id = $order_id;
$this->amount = $amount;
$this->dwidth = $dwidth;
$this->dheight = $dheight;
$this->paneltype = $paneltype;
$this->panelcategory = $panelcategory;
$this->color = $color;
$this->othercolor = $othercolor;
$this->tubes = $tubes;
$this->colorswatch = $colorswatch;
$this->structurepaint = $structurepaint;
$this->uv = $uv;
$this->windowtype = $windowtype;
$this->paintwindow = $paintwindow;
$this->windowsetup = $windowsetup;
$this->glastype = $glastype;
$this->door = $door;
$this->db->insert(self::TABLE_NAME, $this);
return $this->read__entry($this->db->insert_id());
}