only last row is inserting in database - php

Question

I have purchase order form where I am storing product details in session i.e product name, quantity, rate etc. and saving it to database. And at the time of editing purchase order, getting product details from database and storing it in session and appending new product details to session array. It is working fine. But When I submit form then Only last record i.e. newly added record is inserted in database.
here you can assume that I am editing shopping cart after placing order.
My problem is that add,delete items in cart after placing order is logically correct or not? And if yes then How?
This is my code for save and update purchase order.
function save(&$purchase_data,$purchase_id)
{
$success=false;
//Run these queries as a transaction, we want to make sure we do all or nothing
$this->db->trans_start();
if($purchase_data)
{
if (!$purchase_id or !$this->exists($purchase_id))
{
//$purchase_data['purchase_id'] = $purchase_id = $purchase_data['purchase_id'];
$success = $this->db->insert('purchase_order',$purchase_data);
$post_array['cart']=$this->session->userdata('data');
/*print_r($post_array);
exit;*/
$purchase_id=$this->db->insert_id();
$i=0;
foreach($post_array['cart'] as $item)
{
//echo "<pre>"; print_r($item); echo "</pre>";
$query = $this->db->query("SELECT name FROM phppos_items WHERE item_id='".$item['product_id']."'");
foreach ($query->result() as $row)
{
$product_name=$row->name;
}
$product_id=$item['product_id'];
$quantity=$item['quantity'];
$unit=$item['unit'];
$unit_rate=$item['unit_rate'];
$query = $this->db->query("insert into phppos_productdetails(product_id,product_name,quantity,unit,unit_rate,purchase_id) values ('$product_id','$product_name','$quantity','$unit','$unit_rate','$purchase_id')");
$i++;
}
}
else
{
$this->db->where('purchase_id', $purchase_id);
$success = $this->db->update('purchase_order',$purchase_data);
//$this->session->set_userdata('sess_products');
$post_array['cart']=$this->session->userdata('sess_products');
$i=0;
foreach($post_array['cart'] as $item)
{
echo "<pre>"; print_r($item); echo "</pre>";
$query = $this->db->query("SELECT name FROM phppos_items WHERE item_id='".$item['product_id']."'");
foreach ($query->result() as $row)
{
$product_name=$row->name;
}
$product_id=$item['product_id'];
$quantity=$item['quantity'];
$unit=$item['unit'];
$unit_rate=$item['unit_rate'];
$query = $this->db->query("update phppos_productdetails set product_id='$product_id',product_name='$product_name',quantity='$quantity',unit='$unit',unit_rate='$unit_rate' where purchase_id='$purchase_id'");
$i++;
}
}
}
$this->db->trans_complete();
return $success;
}

Answer 1

you have put (where purchase_id='$purchase_id'")
so when the loop executes last time it updates all records with purchase_id as $purchase_id

Answer 2

Your query:
$query = $this->db->query("update phppos_productdetails set product_name='$product_name',product_id='$product_id',quantity='$quantity',unit='$unit',unit_rate='$unit_rate' where purchase_id='$purchase_id'");"
By seeing above query the parameters used in this query like $product_name is out of inner foreach scope.Hence it takes only last record and insert it into database.
If you place this query in inner foreach loop then it will inserts appropriate records as per you required.
Hope this will helps you.