MongoDB 與 .net 6 和 BsonDocument 字段類型

Question

我正在嘗試從我的 MongoDB 數據庫中檢索對象列表。 我必須使用 BsonDocument 在記錄中存儲其他動態數據，但是當我嘗試使用最小的 API 將列表返回到瀏覽器時，我收到以下錯誤。

InvalidCastException: Unable to cast object of type 'MongoDB.Bson.BsonString' to type 'MongoDB.Bson.BsonBoolean'.
AsBooleanGetter(object )
System.Text.Json.Serialization.Metadata.JsonPropertyInfo<T>.GetMemberAndWriteJson(object obj, ref WriteStack state, Utf8JsonWriter writer)
System.Text.Json.Serialization.Converters.ObjectDefaultConverter<T>.OnTryWrite(Utf8JsonWriter writer, T value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.JsonConverter<T>.TryWrite(Utf8JsonWriter writer, ref T value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.Metadata.JsonPropertyInfo<T>.GetMemberAndWriteJson(object obj, ref WriteStack state, Utf8JsonWriter writer)
System.Text.Json.Serialization.Converters.ObjectDefaultConverter<T>.OnTryWrite(Utf8JsonWriter writer, T value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.JsonConverter<T>.TryWrite(Utf8JsonWriter writer, ref T value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.Converters.IEnumerableDefaultConverter<TCollection, TElement>.OnWriteResume(Utf8JsonWriter writer, TCollection value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.JsonCollectionConverter<TCollection, TElement>.OnTryWrite(Utf8JsonWriter writer, TCollection value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.JsonConverter<T>.TryWrite(Utf8JsonWriter writer, ref T value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.Metadata.JsonPropertyInfo<T>.GetMemberAndWriteJson(object obj, ref WriteStack state, Utf8JsonWriter writer)
System.Text.Json.Serialization.Converters.ObjectDefaultConverter<T>.OnTryWrite(Utf8JsonWriter writer, T value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.JsonConverter<T>.TryWrite(Utf8JsonWriter writer, ref T value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.Converters.ListOfTConverter<TCollection, TElement>.OnWriteResume(Utf8JsonWriter writer, TCollection value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.JsonCollectionConverter<TCollection, TElement>.OnTryWrite(Utf8JsonWriter writer, TCollection value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.JsonConverter<T>.TryWrite(Utf8JsonWriter writer, ref T value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.JsonConverter<T>.WriteCore(Utf8JsonWriter writer, ref T value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.Serialization.JsonConverter<T>.WriteCoreAsObject(Utf8JsonWriter writer, object value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.JsonSerializer.WriteCore<TValue>(JsonConverter jsonConverter, Utf8JsonWriter writer, ref TValue value, JsonSerializerOptions options, ref WriteStack state)
System.Text.Json.JsonSerializer.WriteStreamAsync<TValue>(Stream utf8Json, TValue value, JsonTypeInfo jsonTypeInfo, CancellationToken cancellationToken)
System.Text.Json.JsonSerializer.WriteStreamAsync<TValue>(Stream utf8Json, TValue value, JsonTypeInfo jsonTypeInfo, CancellationToken cancellationToken)
System.Text.Json.JsonSerializer.WriteStreamAsync<TValue>(Stream utf8Json, TValue value, JsonTypeInfo jsonTypeInfo, CancellationToken cancellationToken)
Microsoft.AspNetCore.Http.HttpResponseJsonExtensions.WriteAsJsonAsyncSlow<TValue>(Stream body, TValue value, JsonSerializerOptions options, CancellationToken cancellationToken)
Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

我已經嘗試在 object 上使用 BsonExtraElements 屬性（如文檔）並得到相同的結果。

我在Github上放了一個最小樣本。 我的基礎 object 如下所示：

public class BaseCollection
{
    [BsonId]
    [BsonRepresentation(BsonType.ObjectId)]
    public ObjectId Id { get; set; }

    public BsonDocument Metadata { get; set; }
}

我在文件上的唯一記錄是：

{"_id":{"$oid":"61cb03e65b7cd42eedf7a36b"},"Metadata":{"name":"Mauricio","lastname":"Sipmann"}}

我正在查詢以下內容

context.GetCollection("teste").Find(new BsonDocument()).ToList<BaseCollection>()

如果我描述 BaseCollection class 中的每個字段，則 output 有效。

額外的細節。 .net 6 OSx MongoDB 雲

Answer 1

你想返回什么？ 如果你改變你的“去”路線到這個

app.MapGet("/go", async (IMongoDbContext context) => {
    var result = await context.GetCollection("teste").FindAsync(new BsonDocument());
    var list = await result.ToListAsync();
    return list.ToJson();
});

你可能不會得到錯誤。 FindAsync 返回一些 IEnumerable，因此您必須從中獲取列表。