how to prevent user to changing/deleting other user data
I am creating multiuser application. created using php codeigniter And I am seeking the best practice or the best way to prevent user to changing/deleting other user data.

I have some relational tables.

1. tbl_users (user_id, user_name, password)
2. tbl_stores (store_id, user_id, store_name, store_url)
3. tbs_products (product_id, store_id, product_name)

Each user have its own store, and each store may have many products.

So, what is the best ways, to prevent user from deleting other user data? 

I actually, have create some code in the model, but since i am kind of newbie, i am not sure, if this is the right way, my code is like this.

    function remove_product($product_id)
    {
        $this->db->from('products as p');
        $this->db->join('stores as s', 's.id = p.store_id');
        $this->db->where('p.id', $product_id);
        $this->db->where('s.user_id', $this->session->userdata('id'));
    
        if($this->db->count_all_results())
        {
            $this->db->where('id', $product_id);
            return $this->db->delete($this->table);
        }
    }

Please advise if this approach is correct or not, or if there is better way to do this.

Regards
how to prevent user to changing/deleting other user data
===

I am creating multiuser application. created using php codeigniter And I am seeking the best practice or the best way to prevent user to changing/deleting other user data.

I have some relational tables.

1. tbl_users (user_id, user_name, password)
2. tbl_stores (store_id, user_id, store_name, store_url)
3. tbs_products (product_id, store_id, product_name)

Each user have its own store, and each store may have many products.

So, what is the best ways, to prevent user from deleting other user data? 

I actually, have create some code in the model, but since i am kind of newbie, i am not sure, if this is the right way, my code is like this.

    function remove_product($product_id)
    {
        $this->db->from('products as p');
        $this->db->join('stores as s', 's.id = p.store_id');
        $this->db->where('p.id', $product_id);
        $this->db->where('s.user_id', $this->session->userdata('id'));
    
        if($this->db->count_all_results())
        {
            $this->db->where('id', $product_id);
            return $this->db->delete($this->table);
        }
    }

Please advise if this approach is correct or not, or if there is better way to do this.

Regards