Question

有人可以帮帮我吗？我的家伙我需要一个Lambda表达式来处理这个sql语句。

SELECT DISTINCT TOP 1000 hotel.ID
      ,hotel.[LastModifiDate]    as lmf
      ,hotel.[HotelID]   
      ,hotel.[Description]   
      ,hotel.[PercentOff]  as poff
      ,hotel.[ActionState] as acs
      ,hotel.[LanguageID], x.avgPrice AS Price1       
  FROM tb_hotel as hotel 
  LEFT JOIN tb_room_hotel as roomhotel1
        ON (hotel.HotelID = roomhotel1.HotelID)
    LEFT JOIN 
  (
        SELECT AVG(roomhotel2.Price) as avgPrice, roomhotel2.HotelID
        FROM tb_room_hotel1 as roomhotel2
        GROUP BY roomhotel2.HotelID
    ) x
         ON (hotel.HotelID = x.HotelID)
  WHERE hotel.LanguageID=1 ORDER BY avgPrice DESC

GO

我写了这段代码，但代码不正确......

    var hotels1 = tb_hotel .GroupJoin(tb_room_hotel , chid => chid.HotelID, 
crid => crid.HotelID, (chid, crid) => new { chid, crid })
.Where(rec => rec.chid.tb_Language.Title == lang && rec.chid.ActionState != 0)
.SelectMany(@t => @t.crid.DefaultIfEmpty(),(@t, c) => new { @t, c })
.OrderBy(@t => @t.c.Price)
.Where(@t => @t.c.Price > 0).Select(@t => @t.c.Price).Average();

jsfiddle

    table 1 = Hotels
    teble 2 = Room of hotels

////////////////////////
I want show Price one night in Hotel. Sort by ASC & DESC with Lambda expression.

Answer 1

我认为这段代码是正确的。

var hotels1 = tb_hotel.Join(tb_room_hotel, chid => chid.HotelID, crid => crid.HotelID, (chid, crid) => new { chid, crid })
                   .Where(x => x.crid.tb_Language.Title == lang && x.chid.ActionState != 0)
                   .GroupBy(t => new { HID = t.chid.HotelID })
                   .Select(g => new { Average = g.Average(p => p.crid.Price), HID = g.Key.HID }).OrderBy(c => c.Average).ToList();

Lambda Expression加入另一个表格以获得平均值和分类

1 个答案: