Question

I have a view where I store late fees for books not returned on time, here is how I do it in controller action:

    [HttpPost()]
    public ActionResult DisplayTotalBalance(string id)
    {
        DataContext db = new DataContext();

        var totalLateFee = (from p in db.vwCustomer.Where(a => a.CustomerId == id)
                              group p by p.LateFee into g
                              select g.Key).FirstOrDefault();

        return Json(new { totalLateFee });
    }

Here in vwCustomer where I store late fees, a customer may have many late fees listed. For e.g.

CustomerId LateFee
J101        5.0
P202        6.0
J101        2.0
P203        5.0
J101        5.0

How can I sum all the LateFee for J101 and return in controller action?

Answer 1

(from p in db.vwCustomer.Where(a => a.CustomerId == id) select p.LateFee).sum();