Group product by date and sum up quantity and total sales

public ActionResult GetAllSalesRecord()
{
    ASPNETMASTERPOSTEntities db = new ASPNETMASTERPOSTEntities();

    var dataList = db.tblSales.Join(
        db.tblSalesDetails,
        sales => sales.SalesId,
        detail => detail.SalesId,
        (sales, detail) => new { Sales = sales, Detail = detail });

    var modifiedData = dataList.Select(x => new
    {
        SalesDetailId = x.Detail.SalesDetailId,
        Quantity = x.Detail.Quantity,
        ProductId = x.Detail.ProductId,
        ProductName = x.Detail.tblProduct.ProductName,
        SalesId = x.Sales.SalesId,
        OrderDate = x.Sales.OrderDate,
        TotalAmount = x.Sales.TotalAmount
    }).ToList();

    var groupedData = modifiedData
        .GroupBy(x => x.OrderDate.Date) // Group by date (ignoring time)
        .Select(g => new
        {
            OrderDate = g.Key,
            TotalQuantity = g.Sum(x => x.Quantity),
            TotalSales = g.Sum(x => x.TotalAmount)
        }).ToList();

    return Json(groupedData, JsonRequestBehavior.AllowGet);
}

Thank you team for your response, am so much greatful

public ActionResult GetAllSalesRecord()
{
    ASPNETMASTERPOSTEntities db = new ASPNETMASTERPOSTEntities();

    var dataList = db.tblSales
        .Join(
            db.tblSalesDetails,
            sales => sales.SalesId,
            detail => detail.SalesId,
            (sales, detail) => new { Sales = sales, Detail = detail })
        .GroupBy(x => x.Sales.OrderDate) // Grouping by OrderDate
        .Select(group => new
        {
            OrderDate = group.Key,
            TotalQuantity = group.Sum(x => x.Detail.Quantity),
            TotalSales = group.Sum(x => x.Sales.TotalAmount)
        }).ToList();

    return Json(dataList, JsonRequestBehavior.AllowGet);
}