Adding where and sum to lambda expression - linq

Question

I have the below Linq query:
var qry = from Output in db.Outputs
join ShiftHours in db.ShiftHourses on Output.ShiftHour equals ShiftHours.ShiftHour
join ShiftData in db.ShiftDatas on Output.ShiftID equals ShiftData.ShiftID
where ShiftData.ShiftDate == date && ShiftData.Line == line
select new ProgressData()
{
CPM = ShiftData.CPM,
Target = ShiftData.Target,
CurrentOutput = db.Outputs.Sum(x=>x.Quantity),
PercentOfTarget = (db.Outputs.Sum(x=>x.Quantity) / ShiftData.Target) * 100
};
It is almost doing what I want but as it stands, the CurrentOutput lambda expression is returning the sum of the entire Quantity column of the Output table as I am unsure how to add in a 'Where' clause as well as the sum function (and hence the PercentOfTarget is also incorrect).
The where clause needs to be the same as the first where clause (date and line are parameters passed to the method):
where ShiftData.ShiftDate == date && ShiftData.Line == line
Can anyone help?
EDIT: Clarification of CurrentOutput.
In the 'Output' table there can be multiple records for a given 'ShiftData.ShiftDate' and 'ShiftData.Line' combination so I would like to calculate a sum of the 'Output' table 'Quantity' column values for a specified 'ShiftDate' and 'Line'
EDIT: Further clarification
This is some sample data from the Output table (OutputID is an auto-increment PK):
public class Output
{
[Key]
public int OutputId { get; set; }
public int ShiftID { get; set; }
public int Quantity { get; set; }
public int ShiftHour { get; set; }
public virtual ShiftData ShiftData { get; set; }
}
This is some sample data from the ShiftData table (ShiftID is an auto-increment PK, there will be more than one record for each date as further line numbers are added):
public class ShiftData
{
[Key]
public int ShiftID { get; set; }
public DateTime ShiftDate { get; set; }
public string Line { get; set; }
public int CPM { get; set; }
public double Target { get; set; }
}
So using the above sample data, I am trying to populate a ProgressData object:
public class ProgressData
{
public int CPM { get; set; }
public double Target { get; set; }
public int CurrentOutput { get; set; }
public double PercentOfTarget { get; set; }
}
Based on the sample data, I would expect my ProgressData object created for line 1 on 13/2/2014 to be populated as such:
CPM = 5, Target = 200, CurrentOutput = 120, PercentOfTarget = 60

Answer 1

You can try to do group join for that purpose :
var qry = from ShiftData in db.ShiftDatas
join Output in db.Outputs on ShiftData.ShiftID equals Output.ShiftID
into ShiftGroup
where ShiftData.ShiftDate == date && ShiftData.Line == line
select new ProgressData()
{
CPM = ShiftData.CPM,
Target = ShiftData.Target,
CurrentOutput = ShiftGroup.Sum(x=>x.Quantity),
PercentOfTarget = (ShiftGroup.Sum(x=>x.Quantity) / ShiftData.Target) * 100
};
Another thing, I can't see why you need to do join with ShiftHours here, since none of it's property used in select statement.

Answer 2

Just as #har07 posted I managed to get it working using the below. I am posting this for reference as it does answer the original question but I'm going to try and use #har07's code as it's tidier than mine.
var qry = (from Output in db.Outputs
join ShiftHours in db.ShiftHourses on Output.ShiftHour equals ShiftHours.ShiftHour
join ShiftData in db.ShiftDatas on Output.ShiftID equals ShiftData.ShiftID
where ShiftData.ShiftDate == date && ShiftData.Line == line
select new
{
ShiftData.ShiftDate,
ShiftData.Line,
ShiftData.CPM,
ShiftData.Target,
Output.Quantity
}).ToList();
var progress = qry.GroupBy(l => l.ShiftDate).Select(g => new ProgressData()
{
CPM = g.Where(c => c.ShiftDate == date && c.Line == line).Select(c => c.CPM).FirstOrDefault(),
Target = g.Where(c => c.ShiftDate == date && c.Line == line).Select(c => c.Target).FirstOrDefault(),
CurrentOutput = g.Where(c => c.ShiftDate == date && c.Line == line).Sum(c => c.Quantity),
PercentOfTarget = g.Where(c => c.ShiftDate == date && c.Line == line).Sum(c => (c.Quantity / c.Target) * 100)
});
return progress.FirstOrDefault();