unable to access value from data array - php

Question

i want to access unit_id from get_material() method which return data from the modal product_modal.. The function codes..
public function get_material() {
$query = $this->db->get('tbl_receivings_items');
return $query->result();
}
The second function which I want to use unit_id from the above function is
public function get_material_item_unit($p_unit_id){
$sql = "SELECT * FROM tbl_unit WHERE unit_id = ?";
$q = $this->db->query($sql, $p_unit_id);
if($q->num_rows() >0){
return $q->result();
}else{
return null;
}
}
I access both functions from the controller known as manufacture **, in which both functions have been called inside **add_product() function as follows
public function add_product(){
$formRules = array(
array(
'field' => 'prod_name',
'label' => 'Product Name',
'rules' => 'trim|required',
),array(
'field' => 'partner',
'label' => '',
'rules' => 'trim',
),array(
'field' => 'prod_qty',
'label' => 'Quantity To Produce',
'rules' => 'trim|required|greater_than_equal_to[1]',
)
);
$this->form_validation->set_rules($formRules);
if($this->form_validation->run() == TRUE){
$can_be_consumed_value = $this->input->post('can_be_consumed');
$can_be_solded_value = $this->input->post('can_be_sold');
if($can_be_consumed_value == false){
$can_be_consumed_value ="0";
}else{
$can_be_consumed_value ="1";
}
if($can_be_solded_value == false){
$can_be_solded_value ="0";
}else{
$can_be_solded_value ="1";
}
$data =array(
'prod_name' => $this->input->post('prod_name'),
'can_be_consumed' => $can_be_consumed_value,
'can_be_sold' => $can_be_solded_value,
'prod_partner' => $this->input->post('partner'),
'created_by' => $this->input->post('created_by'),
'date_created' => date('Y-m-d'),
'prod_desc' => $this->input->post('prod_desc'),
'prod_qty' =>$this->input->post('prod_qty')
);
$query = $this->product_model->add_product($data);
if($query){
$data['initial_data'] = $this->product_model->get_product_data($query);
$data['material_list'] = $this->product_model->get_material();
$m_list = $this->product_model->get_material();
if($m_list->num_rows() > 0)
{
foreach($m_list->result() as $m){
$data['unit_list'] = $this->product_model->get_material_item_unit($m->unit_id);
}
}
$this->session->set_flashdata('success_msg', 'Product Created Successfully');
$this->load->view('manufacture/manufacture_step_2', $data,'refresh');
}else{
$this->session->set_flashdata('error_msg', 'Sorry! Fail to create product');
redirect('manufacture');
}
}else{
echo '<div class="alert alert-danger error">'.validation_errors().'</div>';
}
}
The add_product() function works properly means that it send data to db.
My Problem: every time I try to access the unit_id through a while loop I get an error of Undefined property: stdClass::$unit_id. i will appreciate your help.
the while loop
$data['initial_data'] = $this->product_model->get_product_data($query);
$data['material_list'] = $this->product_model->get_material();
$m_list = $this->product_model->get_material();
if($m_list->num_rows() > 0)
{
foreach($m_list->result() as $m){
$data['unit_list'] = $this->product_model->get_material_item_unit($m->unit_id);
}
}

Answer 1

I don't know what is the SQL extension that you are using in PHP but normally when you get the results of a query these results are an array of values.
You are trying to get the data like an object and this is the reason that PHP shows you this error because the var $m is not an object.
You can try to do a var_dump($m) and you can see what is the type and the structure of the variable. If $m is an array you must use $m['columnName'] to get the value.