C# 驱动程序和 shell 产生不同的结果

Question

我有两个collection； ProductStemCollections, ProductStems.

    public abstract class Document : IDocument
    {
        [BsonId]
        [BsonRepresentation( BsonType.String )]
        public ObjectId Id { get; set; }
    }

    [BsonCollection( "ProductStemCollections" )]
    public class ProductStemCollection : Document
    {
        public string Name { get; set; }

        [BsonRepresentation( BsonType.String )]
        public List<ObjectId> ProductStems { get; set; } = new List<ObjectId>();
    }

    [BsonCollection( "ProductStems" )]
    public class ProductStem : Document
    {
        [BsonRepresentation(BsonType.String)]
        public ObjectId PromotedProductId { get; set; }

        public string ProductCode { get; set; }
    }

我想聚合词干 collection 中列出的词干，如下所示：

            var query = prodStemCollectionRepo.Collection
                .Aggregate()
                .Lookup( "ProductStems", "ProductStems", "_id", "stems" );

            var strQuery = query.ToString();
            var results = await query.ToListAsync();

这将产生查询

db.ProductStemCollections.aggregate([{ "$lookup" : { "from" : "ProductStems", "localField" : "ProductStems", "foreignField" : "_id", "as" : "stems" } }])

如果我运行在 Cosmos 数据库中进行此查询 shell，我将得到所需的结果：

{
    "_id" : "61694434ba77dc8362d56858",
    "Name" : "Sweden",
    "ProductStems" : [
        "61694434ba77dc8362d56859",
        "61694434ba77dc8362d5685b",
        "61694435ba77dc8362d5685d",
        "61694435ba77dc8362d5685f",
        "61694436ba77dc8362d56861",
        "61694438ba77dc8362d56863"
    ],
    "stems" : [
        {
            "_id" : "61694434ba77dc8362d56859",
            "PromotedProductId" : "61694434ba77dc8362d5685a",
            "ProductCode" : "P1"
        }
        ...
    ]
}

但是，运行使用上面的 C# 代码不会产生相同的结果，即使查询是相同的数组“stems”丢失：

{
    {
        "_id": "61694434ba77dc8362d56858",
        "Name": "Sweden",
        "ProductStems": [
            "61694434ba77dc8362d56859",
            "61694434ba77dc8362d5685b",
            "61694435ba77dc8362d5685d",
            "61694435ba77dc8362d5685f",
            "61694436ba77dc8362d56861",
            "61694438ba77dc8362d56863"
        ]
    }
}

我错过了什么？

Answer 1

好的，所以我最终转向 Mongo Db Atlas。创建了一个集合 class，其中包含一个词干集合及其词干：

        public class AggregatedStemCollection : Document
        {
            public string? Name { get; set; }
            
            [BsonRepresentation(BsonType.String)]
            public List<ObjectId> ProductStems { get; set; } = new List<ObjectId>();

            public List<ProductStem> Stems { get; set; } = new List<ProductStem>();
        }

并修改了林德查询：

            var query = prodStemCollectionRepo.Collection
                .Aggregate()
                .Match( c => c.Name == "Sweden" )
                .Lookup(
                    foreignCollection: productStemRepo.Collection,
                    localField: x => x.ProductStems,
                    foreignField: y => y.Id,
                    @as: ( AggregatedStemCollection asc ) => asc.Stems );

            var results = query.ToList();

C# 驱动程序和 shell 产生不同的结果

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