Everything seems to be fine.

Thanks,
Naveen Prabhu

I have found ananswer. The “Select” line should be
“Select Total_Hours = TC.Productive_Hours_Qty”. If there is a better way please let me know.

Thanks,
Dan

I have a LINQ statement working with multiple joins. It returns the detailed results. My problem lies after the statement has run. I am trying to run a “.Sum” on the query results and it fails stating – Overload resolution failed because not accessible ‘SUM’ accepts this number of arguments.

What am I missing?

Thanks,
Dan

Dim Query = From TC In objTimeWorkedLinq.SA_Timeclocks
Group Join JC In objTimeWorkedLinq.Job_Cds
On TC.Job_Code Equals JC.Job_Code
Into loj1 = Group
From TC1 In loj1.DefaultIfEmpty
Group Join JCT In objTimeWorkedLinq.Job_Type_Cds
On TC1.Job_Type_Code Equals JCT.Job_Type_Code
Into loj2 = Group
From TC2 In loj2.DefaultIfEmpty
Where (p_intAssociateUID = -1
OrElse TC.Associate_UID = p_intAssociateUID)
And (p_intStoreUID = -1
OrElse TC.Store_UID = p_intStoreUID)
And TC.Date_Time >= p_datStartDateTime
And TC.Date_Time <= p_datEndDateTime
And (TC2.Include_Hours_Ind = "Y" Or TC2.Include_Hours_Ind Is Nothing)
Select New With {.Productive_Hours_Qty = TC.Productive_Hours_Qty}

totalHours = Query.SUM

Yes, the similar type of implementation is used for Multiple List joining. First join the 2 list and the output of it is joined with the 3ed one and so on. Here is one post for your reference
Multiple List Join Using LINQ

Thanks,
Naveen Prabhu

I had figured out the non-string null issue.
As an example:

select new
{
RegisterDate = (employee != null) ? employee.RegisterDate : (DateTime?) null,
EmployeeId = (employee != null) ? employee.EmployeeId : (int?) null
};

But i do not think that there is a “left join” in the Linq syntax so am not sure your multiple joining example would work.

What I ended up doing was using several “var” variables to get the multiple left join done; using the previous “var” in the new “var”.
As an example:

var lnqLeftJoin1 =
from aRow in TableA
join bRow in TableB
on aRow.Bid equals bRow.Bid
into LeftJoinGroup
from grpRow in LeftJoinGroup.DefaultIfEmpty()
select new
{
aRow.Aid,
aRow.Bid,
aRow.Cid,
BAddressId = (grpRow != null) ?
grpRow.AddressId
: (int?)null
};

var lnqLeftJoin2 =
from ljRow in lnqLeftJoin1
join cRow in TableC
on ljRow.Cid equals cRow.Cid
into LeftJoinGroup
from grpRow in LeftJoinGroup.DefaultIfEmpty()
select new
{
ljRow.Aid,
ljRow.Bid,
ljRow.Cid,
ljRow.BAddressId,
OrderId = (grpRow != null) ?
grpRow.OrderId
: (int?)null,
OrderDate = (grpRow != null) ?
grpRow.OrderDate
: (DateTime?)null,
};

That seem to work but am not sure if its the best way to handle multiple left join scenario.

In my example i wanted the department name as output so i m taking “null” if no department exists, “null” is the default value of the department name i.e string.

Similarly if you want int output then
1) you can either use 0 in place of null as default value.
2) or you can make the ID field in the department class and nullable int and use the same code.
public int? ID { get; set; }

And for multiple joining, here is the syntax
FROM (A LEFT JOIN B ON A.id = B.id)
LEFT JOIN C ON A.id = C.id;

Hope your doubts are clear, if not feel free to ask .
Thanks,
Naveen Prabhu

1) I need to do 3 left join operators between various tables

2) In your Select New clause for the child record which might be null, you do something like
DepartmentName = dept != null ? dept.Name : null

How do I code that if the child property is not a string but an int?
As an example:
DepartmentID = dept != null ? dept.Id : null

does not work.

Thanks for any help.
Sheir

Yes you can do it. Using Union will help you achieve the result.

If you have 3 lists, List1 , list2 and list3 and if you want list2 in first and list3 in last then use,

var Result = List2.Union(List1).Union(List3)

The result will have what is required.

Thanks,
Naveen Prabhu