Question

I have an object MyObject that contains a date.
I have the following query where TheMonth and TheYear are parameters:

var MyQuery = from a in MyModelDC.MyTable
              where a.Month == TheMonth
              where a.Year == TheYear
              select new MyObject
                   {

                        var1 = a.Day,

                        var2 = (from b in MyModel.MyTable
                                where b.Month == a.Month
                                where b.Year == a.Year
                                select b.Identity).Count()
                    };

I’d like to group the results so that each day occurs only once. Var 2 is a count and at the moment the row of the count is being repeated for each occurrence of Identity instead of being unique per day.

Thanks.

Answer 1

If I understand your requirements correctly, I think this will do what you ask:

var myQuery = from date in MyModelDC.MyTable
              where date.Month == TheMonth && date.Year == TheYear
              group date by date.Day into dayGroup
              select new
              {
                  Day = dayGroup.Key,
                  Count = dayGroup.Count()
              };

Here we first group each item by the day it refers to, then we count each item in the groups so that we only include the items for that group’s specific day.

Update
To use MyObject as the output, you can do this:

var myQuery = from date in MyModelDC.MyTable
              where date.Month == TheMonth && date.Year == TheYear
              group date by date.Day into dayGroup
              select new MyObject
              {
                  var1 = dayGroup.Key,
                  var2 = dayGroup.Count()
              };