How do a linq join of an object to itself?

Question

In the code below I'm trying to join an object to itself. The join kinda works, but it's giving me 4 rows instead of the expected 1 row with both values in the same new object and not 4 copies of the same object. Thanks!!

  var values = rptDataPkg.Datasets.Item(0).Result.AsEnumerable()
 .Where(f => f.Field<int>("RowType") == 3 && 
             f.Field<int>("Category") == 1 && 
           ((f.Field<int>("ItemID") == -1000) || (f.Field<int>("ItemID") == -1001)))
.Select(f => new
{    
   joinOn = 1,
   Proc = f.Field<string>("Item"),
   fieldVal = Convert.ToDecimal(f.Field<decimal?>(field))
}).ToList();

var join = values.Join(values, b1 => b1.joinOn, b2 => b2.joinOn, 
           (b1, b2) => new
            {
                inHVal = b1.fieldVal,
                offSVal = b2.fieldVal
            });

Answer 1

I suspect your values list has two entries. Both will have a joinOn value of 1, so you'll end up with both rows matching themselves and each other. So if the rows are A and B, you'll have

(A, A)
(A, B)
(B, A)
(B, B)