Question

我正在运行以下代码，并收到后续错误：

代码：

using MongoDB.Bson;
using MongoDB.Driver;
using System.Collections.Generic;

namespace MongoBulkWriteSerializationFailure
{
    class Person
    {
        public string Firstname;
        public string Lastname; 
    }

    class DummyClient
    {
        private IMongoCollection<BsonDocument> _collection;

        public DummyClient()
        {
            _collection = (new MongoClient("mongodb://root:password@localhost:27017/")).GetDatabase("my_db").GetCollection<BsonDocument>("persons");
        }

        public void Upsert(Person person)
        {
            List<WriteModel<BsonDocument>> list_of_operations = new List<WriteModel<BsonDocument>>();
            ReplaceOneModel<BsonDocument> write_model = new ReplaceOneModel<BsonDocument>($"{{ 'firstname': '{person.Firstname}', 'lastname': '{person.Lastname}'}}", person.ToBsonDocument());
            write_model.IsUpsert = true;
            list_of_operations.Add(write_model);
            BulkWriteResult<BsonDocument> outcome = _collection.BulkWrite(list_of_operations, new BulkWriteOptions { IsOrdered = false });
            System.Console.WriteLine($"Processed {outcome.ProcessedRequests.Count} item(s)");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            DummyClient client = new DummyClient();

            // Successful Control test:
            ((new MongoClient("mongodb://root:password@localhost:27017/")).GetDatabase("my_db").GetCollection<BsonDocument>("persons")).InsertOne((new Person { Firstname = "John\\1", Lastname = "Smith" }).ToBsonDocument());

            // Successful operation:
            client.Upsert(new Person { Firstname = "Mike", Lastname = "Smith" });

            // Failing operation:
            client.Upsert(new Person { Firstname = "Nick\\1", Lastname = "Smith" });
        }
    }
}

错误：

System.FormatException
  HResult=0x80131537
  Message=Invalid escape sequence in JSON string '\1'.
  Source=MongoDB.Bson
  StackTrace:
   at MongoDB.Bson.IO.JsonScanner.GetStringToken(JsonBuffer buffer, Char quoteCharacter)
   at MongoDB.Bson.IO.JsonScanner.GetNextToken(JsonBuffer buffer)
   at MongoDB.Bson.IO.JsonReader.PopToken()
   at MongoDB.Bson.IO.JsonReader.ReadBsonType()
   at MongoDB.Bson.Serialization.Serializers.BsonDocumentSerializer.DeserializeValue(BsonDeserializationContext context, BsonDeserializationArgs args)
   at MongoDB.Bson.Serialization.Serializers.BsonValueSerializerBase`1.Deserialize(BsonDeserializationContext context, BsonDeserializationArgs args)
   at MongoDB.Bson.Serialization.IBsonSerializerExtensions.Deserialize[TValue](IBsonSerializer`1 serializer, BsonDeserializationContext context)
   at MongoDB.Bson.BsonDocument.Parse(String json)
   at MongoDB.Driver.JsonFilterDefinition`1.Render(IBsonSerializer`1 documentSerializer, IBsonSerializerRegistry serializerRegistry)
   at MongoDB.Driver.MongoCollectionImpl`1.ConvertWriteModelToWriteRequest(WriteModel`1 model, Int32 index)
   at System.Linq.Enumerable.<SelectIterator>d__5`2.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at MongoDB.Driver.Core.Operations.BulkMixedWriteOperation..ctor(CollectionNamespace collectionNamespace, IEnumerable`1 requests, MessageEncoderSettings messageEncoderSettings)
   at MongoDB.Driver.MongoCollectionImpl`1.CreateBulkWriteOperation(IEnumerable`1 requests, BulkWriteOptions options)
   at MongoDB.Driver.MongoCollectionImpl`1.BulkWrite(IClientSessionHandle session, IEnumerable`1 requests, BulkWriteOptions options, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.<>c__DisplayClass23_0.<BulkWrite>b__0(IClientSessionHandle session)
   at MongoDB.Driver.MongoCollectionImpl`1.UsingImplicitSession[TResult](Func`2 func, CancellationToken cancellationToken)
   at MongoDB.Driver.MongoCollectionImpl`1.BulkWrite(IEnumerable`1 requests, BulkWriteOptions options, CancellationToken cancellationToken)
   at MongoBulkWriteSerializationFailure.DummyClient.Upsert(Person person) in C:\code\MongoBulkWriteSerializationFailure\Program.cs:line 28
   at MongoBulkWriteSerializationFailure.Program.Main(String[] args) in C:\code\MongoBulkWriteSerializationFailure\Program.cs:line 46

将要注意的是，主程序中有一些控制操作，这些操作证明了可以在目标DB中插入数据以及在BulkWrite()操作中包含有问题的子字符串的数据。我正在针对MongoDB的4.0.0版进行测试，并使用了官方Mongo C＃驱动程序的2.7.0版。

在BulkWrite()操作之前，有人会知道我在准备数据（例如转义）方面会缺少什么吗？确切地说，在'\'之前应用另一对'\'解决了问题（因此Nick\\1变成Nick\\\\1）。但是我感觉这有点棘手，因为可能还会有其他情况破坏序列化过程。因此，我希望SDK可以提供一个“转义函数”或“包装对象”，以便解决这些序列化陷阱。

Answer 1

如果您在Upsert函数中自行构建FilterDefinition 像这样：

  public void Upsert(Person person)
    {
        var fiterBuilder = Builders<BsonDocument>.Filter;

        var escapedFirstname = filter_builder.Eq("Firstname", person.Firstname);
        var escapedLastname = filter_builder.Eq("Lastname", person.Lastname);

        var filter = fiterBuilder.And(escapedFirstname, escapedLastname);

        List<WriteModel<BsonDocument>> list_of_operations = new List<WriteModel<BsonDocument>>();
        ReplaceOneModel<BsonDocument> write_model = new ReplaceOneModel<BsonDocument>(filter, person.ToBsonDocument());
        write_model.IsUpsert = true;
        list_of_operations.Add(write_model);
        BulkWriteResult<BsonDocument> outcome = _collection.BulkWrite(list_of_operations, new BulkWriteOptions { IsOrdered = false });
        System.Console.WriteLine($"Processed {outcome.ProcessedRequests.Count} item(s)");
    }

它将正确地转义字符。

如果您想知道驱动程序如何执行此操作，则可以在此处看到此情况： https://github.com/mongodb/mongo-csharp-driver/blob/master/src/MongoDB.Bson/IO/JsonScanner.cs#L33

MongoDB中的BulkWrite操作因无效的转义序列而失败

1 个答案: