Dapper - 嵌套对象列表 - 获取重复值

Question

我需要一个 API 端点，它将从单个 json 文件中的这四个表中获取记录。我正在使用 .NET Core 8 Web Api。在 QueryAsync 内部，我尝试了不同的组合，但它没有产生正确的结果。

目前，当我运行时，我可以重复图库和文本块记录，引擎运行良好。例如，这艘船在 Gallery 表中有 37 个图像，在 Textblock 表中有 8 个“BoatId”条目：“317557”。

但是两者都显示37x8 = 296 条记录，如图所示。我被困在这里，请帮忙。我的感觉是我无法使记录清晰，这导致了这个问题。请指导我。

在此输入图片描述

public class Boat
{
public string BoatId { get; set; }
public string CreatedTimestamp { get; set; }
public string UpdatedTimestamp { get; set; }
public string Type { get; set; }
public string Status { get; set; }
public string ListingDate { get; set; }
public string Model { get; set; }
public string VesselName { get; set; }
public int? PriceUSD { get; set; }
public int LOAFeet { get; set; }
public string Manufacturer { get; set; }
public string Category { get; set; }

    public List<Gallery> Gallery { get; set; }
public List<Textblock> Textblocks { get; set; }
public List<Engine> Engines { get; set; }
}


public class Gallery
{
public int GalleryID { get; set; }
public string GalleryBoatId { get; set; }

public string Image { get; set; }
public string Title { get; set; }
public string Description { get; set; }
public string Featured { get; set; }

public int Sort { get; set; }
public string DateTimeStamp { get; set; }
}


public class Textblock
{
public string TextBlockId { get; set; }
public string TextBlockBoatId { get; set; }

public string Language { get; set; }
public string Title { get; set; }
public string Description { get; set; }
public int Sort { get; set; }
}


public class Engine
{
public int EngineId { get; set; }
public string EngineBoatId { get; set; }

public string EngineMake { get; set; }
public string EngineModel { get; set; }
public string EngineYear { get; set; }
public string EngineType { get; set; }
public string EngineLocation { get; set; }
public int Sort { get; set; }
}


public async Task<List<Boat>> GetAllVesselListings()
{

var query = @"SELECT 
boats.BoatId As ListingBoatID, boats.*
,gallery.GalleryBoatId As GalleryBoatID, gallery.*
,Textblock.TextBlockBoatId As TextblockBoatID, textblock.*
,engine.EngineBoatId As EngineBoatID, engine.*

FROM View_IybaBoats boats 
INNER JOIN View_IybaImageGallery gallery ON boats.BoatId = gallery.GalleryBoatId
LEFT OUTER JOIN View_IybaTextBlock textblock ON boats.BoatId = textblock.TextBlockBoatId
LEFT OUTER JOIN View_IybaEngine engine ON boats.BoatId = engine.EngineBoatId

order by boats.BoatId, gallery.Sort
";

var boatDict = new Dictionary<int, Boat>();

var boats = await _db.QueryAsync<Boat, Gallery, Textblock, Engine, Boat>
(query, (boat, gallery, textblock, engine) =>
{
if (!boatDict.TryGetValue(Convert.ToInt32(boat.BoatId), out var currentBoat))
{
currentBoat = boat;

currentBoat.Gallery = new List<Gallery>();

currentBoat.Textblocks = new List<Textblock>();

currentBoat.Engines = new List<Engine>();

currentBoat.Engines.Add(engine);

boatDict.Add(Convert.ToInt32(currentBoat.BoatId), currentBoat);
}
currentBoat.Gallery.Add(gallery);
currentBoat.Textblocks.Add(textblock);

return currentBoat;
},
splitOn: "ListingBoatID,GalleryID,TextBlockId,EngineId");

return boats.Distinct().ToList();

}

我尝试将它们放在 if(!boatDict.TryGetValue... 语句中，然后每个值只有一个值。

currentBoat.Gallery.Add(画廊); currentBoat.Textblocks.Add(textblock);

我需要使图库和文本块仅保留不同的值，但它没有发生。请推荐。

我已经浏览了这个网站上的很多帖子，代码看起来没有任何问题，但结果没有出来。

Answer 1

通过

boats

得到

.QueryAsync()

后，可以对投影中的记录进行分组/区分。

var boats = await _db.QueryAsync<Boat, Gallery, Textblock, Engine, Boat>QueryAsync(/* ... */);

boats = boats.Select(x => new Boat
    {
        Gallery = x.DistinctBy(y => y.GalleryID).ToList(),
        Textblocks = x.DistinctBy(y => y.TextBlockId).ToList(),
        Engines = x.Engines.ToList()
    })
.ToList();

return boats.Distinct().ToList();