c# - Linq 分组依据与父对象

Question

如何分组才能不丢失父标识符。

我有以下内容

        var grouped = mymodel.GroupBy(l => new { l.AddressId })
            .Select(g => new
            {
                AddressId = g.Key.AddressId,
                Quotes = g.SelectMany(x => x.Quotes).ToList(),
            }).ToList();

返回

{ AddressId1, [Quote1, Quote2, Quote3...]}

{ AddressId2, [Quote12, Quote5, Quote8...]}

现在我想按 Quote.Code 和 Quote.Currency 对它们进行分组，这样每个地址都有 1 个对象报价(也就是说，如果属于该地址的所有 4 个报价都具有相同的代码和货币)。我想要那个对象中的货币总和。

这行得通，但我不知道如何将地址添加到此结果:

        var test = grouped.SelectMany(y => y.Quotes).GroupBy(x => new { x.Code, x.Currency }).Select(g => new 
        {
            test = g.Key.ToString()
        });}

每当我尝试将 AddressId 添加到结果时，这会产生编译错误:

        var test1 = grouped.SelectMany(y => y.Quotes, (parent, child) => new { parent.AddressId, child }).GroupBy(x => new { x.Provider, x.Code, x.Currency, x.OriginalCurrency }).Select(g => new
        {
            test = g.Key.ToString(),
            Sum = g.Sum(x => x.Price)
        });

还有编译错误:

        var test1 = grouped.Select(x => new { x.AddressId, x.Quotes.GroupBy(y => new { y.Provider, y.Code, y.Currency, y.OriginalCurrency }).Select(g => new
        {
            addr = x.AddressId,
            test = g.Key.ToString(),
            Sum = g.Sum(q => q.Price)
        };

Answer 1

我会这样做:

    var grouped = mymodel.GroupBy(l => new { l.AddressId })
        .Select(g => new
        {
            AddressId = g.Key.AddressId,
            QuotesByCode = g.SelectMany(x => x.Quotes)
                            .GroupBy(x=>x.Code)
                            .Select(grp=>new
                              {
                                Code = grp.Key.Code,
                                SumOfCurrency=grp.Sum(z=>z.Currency)
                              }).ToList(),
        }).ToList();