c# - Linq 查询组按权重

Question

AllWordIDsAndWeightings是Dictionary<int, double>出现在搜索查询中的单词的唯一 ID，以及它们相应的权重。

给定以下查询：

returnedObjectIDs = new List<int>(db.WordObjectMaps
    .Where(c =>
        c.ForObjectTypeID == TopicObjectTypeID
        && AllWordIDsAndWeightings.Select(w=> w.Key).ToList().Contains(c.WordID)
    )
    .GroupBy(c => c.ForObjectID)
    .Select(c => c.Key)
);

我想修改它，以便：

group by 语句包含word frequency * word weighting每个单词的总和。然后我可以按此值降序排序并获取最高n记录。

这可能吗？

标签： c#asp.netlinq

Answer 1

returnedObjectIDs = new List<int>(db.WordObjectMaps
    .Where(c =>
        c.ForObjectTypeID == TopicObjectTypeID
        && AllWordIDsAndWeightings.ContainsKey(c.WordID)
    )
    .Select(c => new { Word = c, Weight = AllWordIDsAndWeightings[c.WordID])
    .GroupBy(c => x.Word.Value * c.Weight) // replace with your condition
    .Select(c => c.Key)
);