Reputation: 1981
I want to create an index for a query, I want to return to my view a list of Audio items along with statistics for these items, which are TotalDownloads & TotalPlays.
Here are my relevant docs:
Audio
- Id
- ArtistName
- Name
AudioCounter
- AudioId
- Type
- DateTime
Here is my current Index:
public class AudioWithCounters : AbstractMultiMapIndexCreationTask<AudioWithCounters.AudioViewModel>
{
public class AudioViewModel
{
public string Id { get; set; }
public string ArtistName { get; set; }
public string Name { get; set; }
public int TotalDownloads { get; set; }
public int TotalPlays { get; set; }
}
public AudioWithCounters()
{
AddMap<Audio>(audios => from audio in audios
select new
{
Id = audio.Id,
ArtistName = audio.ArtistName,
Name = audio.Name,
TotalDownloads = 0,
TotalPlays = 0
});
AddMap<AudioCounter>(counters => from counter in counters
where counter.Type == Core.Enums.Audio.AudioCounterType.Download
select new
{
Id = counter.AudioId,
ArtistName = (string)null,
Name = (string)null,
TotalDownloads = 1,
TotalPlays = 0
});
AddMap<AudioCounter>(counters => from counter in counters
where counter.Type == Core.Enums.Audio.AudioCounterType.Download
select new
{
Id = counter.AudioId,
ArtistName = (string)null,
Name = (string)null,
TotalDownloads = 0,
TotalPlays = 1
});
Reduce = results => from result in results
group result by result.Id
into g
select new
{
Id = g.Key,
ArtistName = g.Select(x => x.ArtistName).Where(x => x != null).First(),
Name = g.Select(x => x.Name).Where(x => x != null).First(),
TotalDownloads = g.Sum(x => x.TotalDownloads),
TotalPlays = g.Sum(x => x.TotalPlays)
};
}
}
However, my TotalDownloads
& TotalPlays
are always 0 even though there should be data in there. What am I doing wrong?
Upvotes: 0
Views: 128
Reputation: 6839
In the reduce function, replace .First()
with .FirstOrDefault()
, then it works.
Besides that, there is a typo in the second map-function, because you are filtering on the same AudioCounterType.Download.
Upvotes: 2