Linq加入两个列表，按结果分组并选择不同的值

Question

我计划加入 2 个列表，并按条码分组，并获得 reducePrice 和 ItemPrice 列的不同值。我应该如何在 Linq 中实现这一点？ （我想要相交结果。我不想要来自 list2 的数据，例如 Barcode 003,004,005） 这是我尝试过的。

var sameJanWithDiffPriceList3 = (from item in list1                                                 
                                 join t in list2 on item.BarcodeNo equals t.BarcodeNo
                                 group item by item.BarcodeNo
                                 into grp
                                 select new
                                 {
                                     BarcodeNo = grp.Key,
                                     ReducedPrice = grp.Select(x => x.ReducedPrice).Distinct().Count(),
                                     ItemPrice = grp.Select(x => x.ItemPrice).Distinct().Count()
                                  }).ToList();

列表 1

Barcode	reducedPrice	ItemPrice
000	100	120
000	320	420
001	200	360
001	400	860
002	120	160
099	120	160

清单 2

Barcode	reducedPrice	ItemPrice	ItemCode
000	100	120	00
001	200	360	01
002	120	160	02
003	120	160	02
004	120	160	02
005	120	160	02

我想要的结果

Barcode	Count(DistinctReducedPrice)	Count(DistinctItemPrice)
000	2	2
001	3	3
002	1	1
099	1	1

我得到的结果

Barcode	Count(DistinctReducedPrice)	Count(DistinctItemPrice)
000	2	2
001	2	2
002	1	1
099	1	1

Answer 1

您可以使用以下查询

var sameJanWithDiffPriceList3 = (from item in list1
      join t in list2 on item.Barcode equals t.Barcode into joined
      from j in joined.DefaultIfEmpty()
      select new
      {
          Barcode = item.Barcode,
          reducedPrice = item.reducedPrice + "," + j.reducedPrice,
          ItemPrice = item.ItemPrice + "," + j.ItemPrice,
      }
      into grp
      group grp by new { grp.Barcode }
      into result
      select new
      {
         Barcode = result.Key,
         DistinctReducedPrice = string.Join(",", result.Select(a => a.reducedPrice).ToArray()).ToString().Replace(",0","").Split(',').Distinct().Count(),
         DistinctItemPrice = string.Join(",", result.Select(a => a.ItemPrice).ToArray()).ToString().Replace(",0", "").Split(',').Distinct().Count()
      }).ToList();

Answer 2

这应该可以解决问题：

var list2 = new List<(string Barcode,int reducedPrice, int ItemPrice,string ItemCode)>{
    ("000",100,120,"00"),
    ("001",200,360,"01"),
    ("002",120,160,"02"),
    ("003",120,160,"02"),
    ("004",120,160,"02"),
    ("005",120,160,"02")
};

var list1 = new List<(string Barcode,int reducedPrice, int ItemPrice)>{
    ("000",100,120),
    ("000",320,420),
    ("001",200,360),
    ("001",400,860),
    ("002",120,160),
    ("099",120,160)
};


var result = list1.Select(x=>new {x.Barcode,x.reducedPrice,x.ItemPrice})
    .Concat(list2.Select(x=>new {x.Barcode,x.reducedPrice,x.ItemPrice}))
    .GroupBy(
        x=>x.Barcode,
        (k,v)=>new {
            Barcode=k,
            DistinctReducedPrice=v.Select(x=>x.reducedPrice).Distinct().Count(),
            DistinctItemPrice=v.Select(x=>x.ItemPrice).Distinct().Count()
        }
    )
    .ToList();

编辑：对于您的新需求（仅交集），您可以稍微修改上面的代码：

var commonKey = list1.Select(x=>x.Barcode).Intersect(list2.Select(x=>x.Barcode)).ToHashSet();

var result = list2.Where(x=>commonKey.Contains(x.Barcode)).Select(x=>new {x.Barcode,x.reducedPrice,x.ItemPrice})
    .Concat(list1.Where(x=>commonKey.Contains(x.Barcode)).Select(x=>new {x.Barcode,x.reducedPrice,x.ItemPrice}))
    .GroupBy(
        x=>x.Barcode,
        (k,v)=>new {
            Barcode=k,
            DistinctReducedPrice=v.Select(x=>x.reducedPrice).Distinct().Count(),
            DistinctItemPrice=v.Select(x=>x.ItemPrice).Distinct().Count()
        }
    )
    .ToList();

/*Result:
Barcode DistinctReducedPrice DistinctItemPrice
000     2                    2 
001     2                    2 
002     1                    1 
*/

这仍然没有解释，如果你想要交集，为什么结果有“099”，因为list2不包含它。另外，为什么“001”只有 2 个不同的值（200 和 400；360 和 860），你为什么期望 3 和 3？