Linq - Dynamic query that contain DateTime filed - asp.net-core

Question

I have search like as below picture:
I create query by below code:
StringBuilder query = new StringBuilder();
string OrderBy = null;
switch (sortOrder)
{
case "orderCode_desc":
OrderBy = " OrderCode desc";
break;
case "mobile":
OrderBy = "Mobile";
break;
case "mobile_desc":
OrderBy = "Mobile desc";
break;
case "date":
OrderBy = "OrderDate";
break;
case "date_desc":
OrderBy = "OrderDate desc";
break;
case "orderCode":
default:
OrderBy = "OrderCode";
break;
}
if (filters.SelectedProducts.NotNullString())
{
var SelectedProducts = filters.SelectedProducts.Split(',');
query.Append("(");
for (int i = 0; i < SelectedProducts.Length; i++)
{
query.AppendFormat("uag.oag.ordDet.ProductID == {0}" , SelectedProducts[i]);
if (i != SelectedProducts.Length - 1)
{
query.Append(" || ");
}
}
query.Append(") && ");
}
if (filters.DateFrom != null && filters.DateTo != null)
{
query.AppendFormat("(uag.oag._order.order.OrderDate >= {0} && uag.oag._order.order.OrderDate <= {1} )", filters.DateFrom.Date, filters.DateTo.Date);
}
if (filters.DateFrom != null && filters.DateTo == null)
{
query.AppendFormat("( uag.oag._order.order.OrderDate >= {0} )", filters.DateFrom.Date);
}
if (filters.DateFrom == null && filters.DateTo != null)
{
query.AppendFormat("( uag.oag._order.order.OrderDate <= {0} )", filters.DateTo.Date);
}
string _query = query.ToString();
_query = _query.EndsWith("&& ") ? _query.Remove(_query.Length - 3) : _query;
orders = db.orders
.Join(db.order_statuses, order => order.OrderStatusID, OrderStatus => OrderStatus.OrderStatusID, (order, OrderStatus) => new { order, OrderStatus })
.Join(db.order_details, _order => _order.order.OrderID, ordDet => ordDet.OrderID, (_order, ordDet) => new { _order, ordDet })
.Join(db.agents_info, oag => oag._order.order.AgentID, ag => ag.AgentInfoID, (oag, ag) => new { oag, ag })
.Join(db.users, uag => uag.ag.UserID, u => u.UserID, (uag, u) => new { uag, u })
.AsQueryable()
.Where(_query)
.Select(m => new OrderList
{
OrderID = m.uag.oag._order.order.OrderID,
OrderCode = m.uag.oag._order.order.OrderCode,
OrderDate = m.uag.oag._order.order.OrderDate,
OrderStatus = m.uag.oag._order.OrderStatus.OrderStatusTitle,
TotalPrice = m.uag.oag._order.order.TotalPrice,
Mobile = m.u.Mobile
}).OrderBy(OrderBy).Skip(PageSize * (page - 1)).Take(PageSize).ToList();
I get an error:
Operator '>=' incompatible with operand types 'DateTime' and 'Int32'
here is the same problem, and his problem was solved by use a parameterized query. I used parameterized query but problem does not solved.
How can i solved this problem?

Answer 1

Per the documentation you need to use a public constructor to create a DateTime object, so something like
query.AppendFormat("(uag.oag._order.order.OrderDate >= {0} && uag.oag._order.order.OrderDate <= {1})",
filters.DateFrom.Date.ToString(#"Da\teTi\me(yyyy,M,d)"),
filters.DateTo.Date.ToString(#"Da\teTi\me(yyyy,M,d)"));