Update query fail

Hello,

You need to fetch data from database and then assign updated values and save data. please check the below code.

public JsonResult UpdateInvoiceSale(tblSale sale, List salesDetail, List deleted)
{
    MasterMVCPOS.Helper.AppHelper.ReturnMessage retMessage = new AppHelper.ReturnMessage();
    ASPNETMASTERPOSTEntities db = new ASPNETMASTERPOSTEntities();
    retMessage.IsSuccess = true;

    try
    {
        if (deleted != null)
        {
            foreach (var item in deleted)
            {
                var data = db.tblSalesDetails.Where(x => x.SalesDetailId == item).FirstOrDefault();
                db.tblSalesDetails.Remove(data);
            }
        }

        foreach (var item in salesDetail)
        {
            if (item.SalesDetailId > 0)
            {
                db.Entry(item).State = EntityState.Modified;
                retMessage.Message = "Update successfully!";
            }
            else
            {
                //sale.tblSalesDetails.Add(new tblSalesDetail { ProductId = item.ProductId, UnitPrice = item.UnitPrice, Quantity = item.Quantity, LineTotal = item.LineTotal });
                var prd = db.tblProductStocks.Where(x => x.ProductId == item.ProductId && x.Quantity > 0).FirstOrDefault();
                prd.Quantity = prd.Quantity - item.Quantity;
                db.Entry(prd).State = EntityState.Modified;

                db.tblSalesDetails.Add(item);
                retMessage.Message = "Save successfully!";
            }
        }
        var tblsale = db.tblsale.where(a => a.SalesId = sale.SalesId).FirstOrDefault();
        tblsale = sale;
        db.Entry(tblsale).State = EntityState.Modified;
        db.SaveChanges();
    }
    catch (Exception ex)
    {
        retMessage.IsSuccess = false;
    }

    return Json(retMessage, JsonRequestBehavior.AllowGet);
}

Thanks

Vishal Joshi