how to retrieve foreign key from another table if i fetch its giving me all the primary ids instead

how to retrieve foreign key from another table if i fetch its giving me all the primary ids instead.
What am trying to achieve is when i select the primary from table A all the foreign key in table B with the same value must be select

public function getAllInvoice(){
$this->db->query(“SELECT tbl_invoice_items., tbl_invoice_total.,tbl_invoice_total.invoices_id FROM tbl_invoice_items
INNER JOIN tbl_invoice_total
ON tbl_invoice_items.invoice_fk = tbl_invoice_total.invoices_id
ORDER BY oder_date DESC”);
$results = $this->db->resultSet();
return $results;
}