$this->db->group_by() and adding the quantity - php

Question

I have this in my receipt UI(Note: This is only from one user):
Item_Name | Quantity | Price | Total
Panty | 2 | 50 | 100
Bra | 1 | 35 | 35
Panty | 2 | 50 | 100
As you can see the user gets the Panty TWICE!
I want my UI to be looking like this:
Item_Name | Quantity | Price | Total
Panty | 4 | 50 | 100
Bra | 1 | 35 | 35
As you can see the Panty's that the user buys groups together, but in my query instead of Panty having 4 Quantity it still has 2
Here is my Code:
public function getClientReservation($name){
$this->db->select('*');
$this->db->from('tbl_item_availed');
$this->db->join('tbl_items','tbl_items.Item_ID = tbl_item_availed.Item_ID');
$this->db->join('user_account','user_account.Account_no = tbl_item_availed.Account_no');
$this->db->where('Username',$name);
$this->db->where('isReserve',1);
$this->db->where('Active',1);
$this->db->group_by('tbl_items.Item_Name');
$query = $this->db->get();
return $query->result();
}
Please help!
This is the table tbl_item_availed by the way:
Item_availed_id | Item_ID | Quantity | Account_no
1 | 1 | 2 | 5
2 | 2 | 1 | 5
3 | 1 | 2 | 5
table tbl_items:
Item_ID | Price | Item_Name
1 | 100 | Panty
2 | 35 | Bra
table user_account:
Account_no | Firstname | Lastname
1 | LeBron | James
2 | Dwyane | Wade
3 | Wilt | Chamberlain
4 | Michael | Jordan
5 | Charles | Barkley

Answer 1

Try this.
public function getClientReservation($name){
$this->db->select('tbl_items.`Item_Name`, SUM(tbl_item_availed.`Quantity`) AS quantity, tbl_items.`Price`, (tbl_items.`Price`*(SUM(tbl_item_availed.`Quantity`))) AS total');
$this->db->from('tbl_item_availed');
$this->db->join('tbl_items','tbl_items.Item_ID = tbl_item_availed.Item_ID');
$this->db->join('user_account','user_account.Account_no = tbl_item_availed.Account_no');
$this->db->where('Username',$name);
$this->db->where('isReserve',1);
$this->db->where('Active',1);
//$this->db->group_by('tbl_items.Item_Name');//do not use this line unless item name is unique
//group by item id
$this->db->group_by('tbl_items.Item_ID');
$query = $this->db->get();
return $query->result();
}
Also use GROUP BY for Item_ID (assuming it is unique), not Item_Name unless it is unique.
Side note:
Moreover, use Account_no instead of username in WHERE clause. If you want to modify it, just replace this line
$this->db->where('Username',$name);
with
$this->db->where('Account_no',$account_no);