Question

I have a list of ForecastData and it looks like this:

public class ForecastData
{
    public string SalesID {get;set;}
    public string Customer {get;set;}
    public string Vendor {get;set;}
    public string Division {get;set;}
    public int Year {get;set;}
    public decimal Amount {get;set;}
}

I need to display a list of every distinct “SalesID” for each “Customer” that has an Amount > 0 where the year is THIS YEAR.

Currently, I’m grouping by Customer, but because I can have multiple “Amounts” for the same Customer and SalesID in my dataset, I’m not getting the results I expect. My results show:

1. Customer1 User1 $100
2. Customer1 User1 $200
3. Customer1 User1 $300
4. Customer1 User2 $100
5. Customer1 User2 $200

But what I want is

1. Customer1 User1 $600
2. Customer1 User2 $300

Here’s my expression:

var forecasts = (List<ForecastData>)cache.Get(_RAW_FORECAST_DATA_KEY, null);

foreach(var custGroup in forecasts.Where(f => f.Year == DateTime.Now.Year).GroupBy(f => f.Customer))
{
    if(custGroup.Count() > 1) // There's more than one forecast for this customer
    {
        foreach(var instance in custGroup)
        {
            toReturn.Add(new MultipleCustomer(custGroup.Key)
            {
                Salesperson = instance.SalesPersonId,
                Forecast = instance.Amount
            });
        }
    }
}

return toReturn;

Answer 1

I think if you change your query so that you have an “outer” GroupBy and an “inner” GroupBy, it will solve your problem:

var forecasts = (List<ForecastData>)cache.Get(_RAW_FORECAST_DATA_KEY, null);

var forecastGroups = forcasts
    .Where(f => f.Year = DateTime.Now.Year)
    .GroupBy(f => f.Customer)
    .Where(grp => grp.Count() > 1)
    .Select(grp => new { Key = grp.Key, SalesGroups = grp.GroupBy(f => f.SalesId) });

foreach(var custGroup in forecastGroups)
{
    if(custGroup.SalesGroups.Count() > 1)
    {
        foreach(var salesGroup in custGroup.SalesGroups)
        {
            toReturn.Add(new MultipleCustomer(custGroup.Key)
            {
                Salesperson = salesGroup.Key,
                Forecast = salesGroup.Sum(f => f.Amount)
            });
        }
    }
}

return toReturn;