Nested GroupBy using Linq

Question

I'm trying to perform a nested GroupBy using Linq and I'm not able to get it to work. My code is the following:

    var summaryFile = new RemittanceCenterFilesSummaryListModel
        {
            RemittanceFilesSummary = remittanceCenterSummaryListModel.RemittanceBatchSummaryRecord.GroupBy(x => new { x.FileId, x.SourceFileName  })
                .Select(x => new RemitanceCenterFileSummarizedModel
                {
                    FileId = x.Key.FileId,
                    SourceFileName = x.Key.SourceFileName,
                    Batches = x.ToList().GroupBy(b => new { b => b.BatchCode })
                      .Select(c => new RemittanceCenterBatchSummarizedModel
                      {
                           FileId = x.Key.FileId,
                           SourceFileName = x.Key.SourceFileName,
                           BatchCode = c.Key,
                           BatchType = c.Key,
                           DetailRecordCountAdc = x.Count(y => y.BillingSystemCode == BillingSystemCode.Adc),
                           DetailRecordCountNotAdc = x.Count(y => y.BillingSystemCode == BillingSystemCode.Exceed),
                           AmountAdc = x.Where(y => y.BillingSystemCode == BillingSystemCode.Adc).Sum(y => y.PaymentAmount),
                           AmountNotAdc = x.Where(y => y.BillingSystemCode == BillingSystemCode.Exceed).Sum(y => y.PaymentAmount),
                           AmountTotal = x.Sum(y => y.PaymentAmount),
                      });
                    ScannedBatchCount = x.Count(y => y.BatchType == "S"),
                    ScannedBatchAmount = x.Where(y => y.BatchType == "S").Sum(y => y.PaymentAmount),
                    NonScannedBatchCount = x.Count(y => y.BatchType != "S"),
                    NonScannedBatchAmount = x.Where(y => y.BatchType != "S").Sum(y => y.PaymentAmount), 
                }).ToList()
        };

The first GroupBy is working correctly, however when I try to GroupBy the Batches field I'm getting the following build error:

Error 76 Invalid anonymous type member declarator. Anonymous type members must be declared with a member assignment, simple name or member access.

The error is highlighted here:

    Batches = x.ToList().GroupBy(b => new { b => b.BatchCode })

Any suggestions ?

Answer 1

You mean

Batches = x.ToList().GroupBy(b => b.BatchCode)

There is no need to create an anonymous type if you want to group by only one property.

---

If you need an anonymous type, the syntax would be

Batches = x.ToList().GroupBy(b => new { b.BatchCode })

you used another lambda operator (b => new {b => b.BatchCode}) inside the anonymous type, which was invalid.