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Ordering issue with Groupby in Linq

I am facing issues in using order by with group by in linq queries. when I apply group by after order by the ordering is being lost using the following code.
I want to sort all the conversations where type is in ascending. I doubt using Select(x=>x.FirstOrDefault()) is creating some issue.
I am using LINQ queries like this
DateTime? convStartDate = DateTime.Now.AddDays(-90);
DateTime? convEndDate = DateTime.Now;
var limit = 1000;
var offset = 0;
var query = (from conversation in db.textMessagesconversation
join msgParticipants in db.participants on conversation.Id equals msgParticipants.ConversationId
join msg in db.MsgMessages on conversation.Id equals msg.ConversationId
where msgParticipants.UserId == userID && ( (String.IsNullOrEmpty(convStartDate.ToString()) || msg.DateCreatedTime >= convStartDate)
&& (String.IsNullOrEmpty(convEndDate.ToString()) || msg.DateCreatedTime <= convEndDate)
select new RawConversation
{
LastMessageContent = msg.Content,
LastMessageDateTime = msg.DateCreatedTime,
IsAttachment = msg.IsAttachment,
SenderId = msg.SenderId,
MessageId = msg.Id,
Type = conversation.Type,
Name = conversation.Name,
Id = conversation.Id
});
query = query.OrderBy(x => x.Type);
var textmessagesList= query.GroupBy(x=>x.Id).Select(x=>x.FirstOrDefault()).Skip(offset).Take(limit).ToList();

Add conditions after muilti join LINQ expression

I've got a Linq query with 5 joins/tables, with predefined conditions.
Because I need the query multiple times I've created a function which returns the default LINQ query as an IQueryable.
public static IQueryable<MroomLinqModel> GetDefaultQuery(CustomerContext CustomerCtx)
{
var Mrooms = (from mr in CustomerCtx.Mrooms
join m in CustomerCtx.Moves on mr.MoveId equals m.MoveId
join mg in CustomerCtx.mgroup on m.MgroupId equals mg.MgroupId
join s in CustomerCtx.Status on m.StatusId equals s.StatusId
join rt in CustomerCtx.Roomtypes on mr.RoomtypeId equals rt.Key
join g in CustomerCtx.Guests on m.Mgroup.GuestId equals g.GuestId
where
Math.Abs(mg.Status) != (int)IResStatus.InComplete &&
s.Visible
select new MroomLinqModel
{
OpenDepositPayments = mg.DepositPayments.Any(dp => !dp.Paid),
RoomHidden = (mr.RoomId == null ? true : mr.Room.Hidden),
StatusVisible = s.Visible,
MroomId = mr.MroomId,
MoveId = m.MoveId,
MgroupId = mg.MgroupId,
StatusId = s.StatusId,
StatusFlags = s.Flags,
BackgroundColor = s.Background_Argb,
TextColor = s.Foreground_Argb,
PersonCount = m.Movegroups.Sum(m => m.PersonCount),
MoveCount = mg.Moves.Count(),
RoomId = mr.RoomId,
PMSMroomId = mr.PMS_Id,
PMSMoveId = m.PMS_Id,
PMSMgroupId = mg.MgroupId_Casablanca,
From = mr.From,
Until = mr.Until,
EditableState = m.EditableState,
MroomStatus = mr.Status,
RoomtypeUsage = mr.Roomtype.Usage,
BookingReference = mg.ReferenceNumber,
Guest = g
});
return Mrooms;
}
Now I would like to add some conditions afterwards like:
Query = GetDefaultQuery.Where(q => !q.RoomHidden && q.From <= dtLoadEnd && dtLoadStart <= q.Until);
Query = Query.Where(q => q.RoomtypeUsage == RoomtypeUsageType.Roomplan);
This works fine but takes a lot more time to execute as if I add all conditions directly to the first LINQ query.
How do I form the query to access the original tables and generate a fast query?

Since all your condition match the table where you are joining the other tables you can add the conditions before your multi join, I got 2 suggestions for you, either create another method that filters your conditions predefined or add to your method optional filters like so :
public static IQueryable<MroomLinqModel> GetDefaultQuery(CustomerContext CustomerCtx, bool? roomHidden, DateTime? dtLoadEnd
/* you can add more parameters but for demonstrations purposes i'm only describing this 2*/)
{
var query = CustomerCtx.Mrooms;
if(roomHidden.HasValue)
{
query = query.Where( q=>q.From == roomHidden.Value)
}
if(dtLoadEnd .HasValue)
{
query = query.Where( q=>q.RoomHidden <= dtLoadEnd.Value)
}
// you can add more conditions
var Mrooms = (from query
join m in CustomerCtx.Moves on mr.MoveId equals m.MoveId
join mg in CustomerCtx.mgroup on m.MgroupId equals mg.MgroupId
join s in CustomerCtx.Status on m.StatusId equals s.StatusId
join rt in CustomerCtx.Roomtypes on mr.RoomtypeId equals rt.Key
join g in CustomerCtx.Guests on m.Mgroup.GuestId equals g.GuestId
where
Math.Abs(mg.Status) != (int)IResStatus.InComplete &&
s.Visible
select new MroomLinqModel
{
OpenDepositPayments = mg.DepositPayments.Any(dp => !dp.Paid),
RoomHidden = (mr.RoomId == null ? true : mr.Room.Hidden),
StatusVisible = s.Visible,
MroomId = mr.MroomId,
MoveId = m.MoveId,
MgroupId = mg.MgroupId,
StatusId = s.StatusId,
StatusFlags = s.Flags,
BackgroundColor = s.Background_Argb,
TextColor = s.Foreground_Argb,
PersonCount = m.Movegroups.Sum(m => m.PersonCount),
MoveCount = mg.Moves.Count(),
RoomId = mr.RoomId,
PMSMroomId = mr.PMS_Id,
PMSMoveId = m.PMS_Id,
PMSMgroupId = mg.MgroupId_Casablanca,
From = mr.From,
Until = mr.Until,
EditableState = m.EditableState,
MroomStatus = mr.Status,
RoomtypeUsage = mr.Roomtype.Usage,
BookingReference = mg.ReferenceNumber,
Guest = g
});
return Mrooms;
}

expecting that CustomerCtx.Mrooms is a DbSet<Mroom> and that Mroom looks like :
public class Mroom {
public int MroomId {get; set;}
[ForeignKey("Move")]
public int MoveId {get; set;} //FK
public virtual Move Move {get; set;} //Navigation property
//configuration may be needed cf annotation
[ForeignKey("Status")]
public int StatusId {get; set;}
public virtual Status Status {get; set;}
//... Mgroup, Guest, ...
}
If it is not the case I suggest you yo refactor your code to use navigation properties.
Then you may use PredicateBuilder of linqkit as follow:
public static IQueryable<MroomLinqModel> GetDefaultQuery(CustomerContext CustomerCtx, Expression<Function<Mroom, bool>> q)
{
Expression<Function<Mroom, bool>> w = PredicateBuilder.New<Mroom>
(s => Math.Abs(s.Mgroup.Status) != (int)IResStatus.InComplete &&
s.Visible);
w = w.And(q);
return
CustomerCtx.Mrooms.
Where(w.Expand()).
Select( x => new MroomLinqModel
{
OpenDepositPayments = x.Mgroup.DepositPayments.Any(dp => !dp.Paid),
RoomHidden = (x.RoomId == null ? true : x.Room.Hidden),
StatusVisible = x.Status.Visible,
MroomId = x.MroomId,
MoveId = x.MoveId,
MgroupId = x.MgroupId,
StatusId = x.Status.StatusId,
StatusFlags = x.Status.Flags,
BackgroundColor = x.Status.Background_Argb,
TextColor = x.Status.Foreground_Argb,
PersonCount = x.Move.Movegroups.Sum(m => m.PersonCount),
MoveCount = x.Mgroup.Moves.Count(),
RoomId = x.RoomId,
PMSMroomId = x.PMS_Id,
PMSMoveId = x.Move.PMS_Id,
PMSMgroupId = x.Mgroup.MgroupId_Casablanca,
From = x.From,
Until = x.Until,
EditableState = x.Move.EditableState,
MroomStatus = x.Move.Status,
RoomtypeUsage = mr.Roomtype.Usage,
BookingReference = x.Mgroup.ReferenceNumber,
Guest = x.Guest
}
);
}
and use it as:
GetDefaultQuery(ctx, q => !q.RoomHidden && q.From <= dtLoadEnd && dtLoadStart <= q.Until);
and or
Expression<Function<Mroom, bool>> w = PredicateBuilder.New<Mroom>(q =>
!q.RoomHidden && q.From <= dtLoadEnd && dtLoadStart <= q.Until);
//some logic
w = w.And(q => q.RoomtypeUsage == RoomtypeUsageType.Roomplan);
GetDefaultQuery(ctx, w);

Linq Include Extra Column in GroupBy Selection

I have a "ReactionSimple" column that I'd like to include in the GroupBy selection but when I include it in the Group By it throws off the returned row count in a big way. Is there a way to include the commented out column in the final grouped selection without throwing off the result count. I'm a LINQ noob.
var reactivityResults = new List<ReactivityResultViewModel>();
var reactivityResults2 = new List<ReactivityResultViewModel>();
var classifications = GetMaterialClassifications(test.TestType);
var antigens = _db.Antigens.ToList();
if (test.ResultSets.Any())
{
var testResult = test.ResultSets.FirstOrDefault();
var dateReported = testResult.DateReported;
var details = testResult.ResultSetDetails.ToList();
if (details.Any())
{
reactivityResults = (from d in details
join a in _db.Antigens on d.AntigenId equals a.AntigenId
join ma in _db.MaterialAntigens on a.AntigenId equals ma.AntigenId
join md in _db.MaterialDefs on ma.MaterialDefId equals md.MaterialDefId
join c in classifications on md.MaterialId equals c.MaterialId
select new ReactivityResultViewModel
{
MaterialId = c.MaterialId,
MaterialName = c.MaterialName,
IsActive = md.IsActive,
ReactionSimple = (ReactionTypeEnum)d.ReactionSimple,
TestId = test.TestId,
AccessionId = test.AccessionId,
PatientFirstName = test.Patient.Party.NameFirst,
PatientLastName = test.Patient.Party.NameLast,
TestType = (TestTypeNoFlagsEnum)test.TestType,
DateReported = dateReported,
ManufacturerId = c.ManufacturerId,
ManufacturerName = c.ManufacturerName
})
.OrderBy(x => x.MaterialName)
.ToList();
var sreactivityResults2 = reactivityResults
.GroupBy(x => new {
x.MaterialId, x.AccessionId, x.DateReported,
x.IsActive, x.ManufacturerId, x.ManufacturerName,
x.MaterialName, x.PatientFirstName, x.PatientLastName,
x.TestId, x.TestType,
//x.ReactionSimple
})
.Select(x => new ReactivityResultViewModel
{
MaterialId = x.Key.MaterialId,
MaterialName = x.Key.MaterialName,
IsActive = x.Key.IsActive,
//ReactionSimple = x.Key.ReactionSimple,
TestId = test.TestId,
AccessionId = test.AccessionId,
PatientFirstName = test.Patient.Party.NameFirst,
PatientLastName = test.Patient.Party.NameLast,
TestType = (TestTypeNoFlagsEnum)test.TestType,
DateReported = dateReported,
ManufacturerId = x.Key.ManufacturerId,
ManufacturerName = x.Key.ManufacturerName
})
.ToList();
var sd2 = sreactivityResults2.ToList();
}
return reactivityResults;

Returning List value using linq C#

Actually I want to return the data from different lists based on Date. When i'm using this i'm getting data upto #Var result but i'm unnable to return the data. The issue with this is i'm getting error #return result. I want to return the data #return result. I'm using Linq C#. Can anyone help me out?
public List<CustomerWiseMonthlySalesReportDetails> GetAllCustomerWiseMonthlySalesReportCustomer()
{
var cbsalesreeport = (from cb in db.cashbilldescriptions
join c in db.cashbills on cb.CashbillId equals c.CashbillId
join p in db.products on cb.ProductId equals p.ProductId
select new
{
Productamount = cb.Productamount,
ProductName = p.ProductDescription,
CashbillDate = c.Date
}).AsEnumerable().Select(x => new ASZ.AmoghGases.Model.CustomerWiseMonthlySalesReportDetails
{
Productdescription = x.ProductName,
Alldates = x.CashbillDate,
TotalAmount = x.Productamount
}).ToList();
var invsalesreeport = (from inv in db.invoices
join invd in db.invoicedeliverychallans on inv.InvoiceId equals invd.InvoiceId
select new
{
Productamount = invd.Total,
ProductName = invd.Productdescription,
InvoiceDate = inv.Date
}).AsEnumerable().Select(x => new ASZ.AmoghGases.Model.CustomerWiseMonthlySalesReportDetails
{
Productdescription = x.ProductName,
Alldates = x.InvoiceDate,
TotalAmount = x.Productamount
}).ToList();
var abc = cbsalesreeport.Union(invsalesreeport).ToList();
var result = (from i in abc
group i by new { Date = i.Alldates.ToString("MMM"), Product = i.Productdescription } into grp
select new { Month = grp.Key, Total = grp.Sum(i => i.TotalAmount) });
**return result;**
}

You can either convert your result to a List before returning it using return result.ToList() or make your method return an IEnumerable<CustomerWiseMonthlySalesReportDetails> instead of List.
As your result is an enumeration of anonymous types you have to convert them to your CustomerWiseMonthlySalesReportDetails-type first:
select new CustomerWiseMonthlySalesReportDetails{ Month = grp.Key, Total = grp.Sum(i => i.TotalAmount) });
Assuming your type has exactly the members returned by the select.
EDIT: So your code should look like this:
var result = (from i in abc
group i by new { Date = i.Alldates.ToString("MMM"), Product = i.Productdescription } into grp
select new CustomerWiseMonthlySalesReportDetails{ Month = grp.Key, Total = grp.Sum(i => i.TotalAmount) });
return result.ToList();

You can assume Alldates property if is date of one of groups that month of date is in right place:
var result = (from i in abc
group i by new { Date = i.Alldates.ToString("MMM"), Product = i.Productdescription }
into grp
select new CustomerWiseMonthlySalesReportDetails{
Productdescription = grp.Key.Product,
TotalAmount = grp.Sum(i => i.TotalAmount),
Alldates =grp.First(i=>i.Alldates ) })
.ToList();

Not getting the difference between two list by using linq

I have two lists as follows:
var SeparatedEmployees = (from s in DataContext.HRM_EMP_TRMN.AsEnumerable()
where s.TRMN_FINL_STUS == "SA" && ((Convert.ToDateTime(s.TRMN_EFCT_DATE)).Year).ToString() == Year && ((Convert.ToDateTime(s.TRMN_EFCT_DATE)).Month).ToString() == HRMD_COMMON.ReturnMonthName(Month)
join e in DataContext.VW_HRM_EMPLOYEE on s.EMP_CODE equals e.EMP_CODE
where e.ACTIVE_STATUS == "A"
select new HRM_EMP_FINL_STMT_MSTModel
{
EMP_CODE = s.EMP_CODE,
EMP_NAME = e.EMP_NAME,
DIVI_CODE = e.DIVI_CODE,
DIVI_NAME = e.DIVI_NAME,
EMP_DESIG_CODE = e.EMP_DESIG_CODE,
EMP_DESIG_NAME = e.EMP_DESIG_NAME,
JOINING_DATE = HRMD_COMMON.ReturnOnlyDate(Convert.ToDateTime(e.JOINING_DATE)),
TRMN_TYPE = HRMD_COMMON.ReturnTerminationType(s.TRMN_TYPE),
TRMN_EFCT_DATE = HRMD_COMMON.ReturnOnlyDate(Convert.ToDateTime(s.TRMN_EFCT_DATE)),
LAST_SAL_PROS_MON = HRMD_COMMON.ReturnMonthName(s.LAST_SAL_PROS_MON),
FINL_STMT_REM = s.TRMN_REM
}).ToList();
var ConfirmedEmployees = (from c in DataContext.HRM_EMP_FINL_STMT_MST.AsEnumerable()
where ((Convert.ToDateTime(c.FINL_STMT_DATE)).Year).ToString() == Year && ((Convert.ToDateTime(c.FINL_STMT_DATE)).Month).ToString() == HRMD_COMMON.ReturnMonthName(Month)
join e in DataContext.VW_HRM_EMPLOYEE on c.EMP_CODE equals e.EMP_CODE
join s in DataContext.HRM_EMP_TRMN on c.EMP_CODE equals s.EMP_CODE
select new HRM_EMP_FINL_STMT_MSTModel
{
EMP_CODE = s.EMP_CODE,
EMP_NAME = e.EMP_NAME,
DIVI_CODE = e.DIVI_CODE,
DIVI_NAME = e.DIVI_NAME,
EMP_DESIG_CODE = e.EMP_DESIG_CODE,
EMP_DESIG_NAME = e.EMP_DESIG_NAME,
JOINING_DATE = HRMD_COMMON.ReturnOnlyDate(Convert.ToDateTime(e.JOINING_DATE)),
TRMN_TYPE = HRMD_COMMON.ReturnTerminationType(s.TRMN_TYPE),
TRMN_EFCT_DATE = HRMD_COMMON.ReturnOnlyDate(Convert.ToDateTime(s.TRMN_EFCT_DATE)),
LAST_SAL_PROS_MON = HRMD_COMMON.ReturnMonthName(s.LAST_SAL_PROS_MON),
FINL_STMT_REM = s.TRMN_REM
}).ToList();
Tyring to remove the items from the first list, which are also in second list.
var FinalSeparatedEmployees = (from item in SeparatedEmployees
where !ConfirmedEmployees.Contains(item)
select item).ToList();
Tried this one too:
FinalSeparatedEmployees = SeparatedEmployees.Except(ConfirmedEmployees).ToList<HRM_EMP_FINL_STMT_MSTModel>();
But not getting the accurate result. What I'm missing? Thanks.

Its better to use EMP_CODE because your objects are not comparable.
var ids = ConfirmedEmployees.Select(x => x.EMP_CODE).ToList();
var FinalSeparatedEmployees = (from item in SeparatedEmployees
where !ids.Contains(item.EMP_CODE)
select item).ToList();