UpdateOneAsync 不支持表达式树

Question

调用 UpdateOneAsync 时，使用此包装器：

    public async Task<UpdateResult> UpdateDocument<T>(
        string sCollectionName, 
        Expression<Func<T, bool>> filter, 
        UpdateDefinition<T> update,
        bool bUpsert,
        System.Threading.CancellationToken cancellationToken
        )
    {
        IMongoDatabase db = _mongoClient.GetDatabase(_optionsMonitor.CurrentValue.databasename);

        IMongoCollection<T> collection = db.GetCollection<T>(sCollectionName);

        return await collection.UpdateOneAsync<T>(filter, update, new UpdateOptions() { IsUpsert = bUpsert }, cancellationToken);
    }

像这样：

private async Task<Models.Errors> UpdateDbOnSyncServerToBoardUpdate(
        CancellationToken cancel,
        MongoDB.Bson.BsonDocument bsonDocConfigurationToUpdate,
        DateTime dtUpdated,
        string sId,
        int iObjectId,
        string sAppName,
        string sModelName
        )
    {
        MongoDB.Driver.UpdateResult updateResult = null;
        Models.Errors errors = null;

        try
        {
            updateResult = await _db.UpdateDocument<Models.Database.NodeBoardModel>(
                Constants.NodeBoardCollectionName,
                node => node.Id == sId && 
                node.RemoteBoard.apps.SingleOrDefault(
                    app => app.appname == sAppName).objects.
                    SingleOrDefault(model => model.name == sModelName).config_docs.
                    Any(config => config.config_id == iObjectId),
                MongoDB.Driver.Builders<Models.Database.NodeBoardModel>.Update.
                Set(
                    node => node.RemoteBoard.apps[-1].objects[-1].config_docs[-1].config_doc, bsonDocConfigurationToUpdate).
                Set(
                    node => node.RemoteBoard.apps[-1].objects[-1].config_docs[-1].config_dt, dtUpdated),
                false,
                cancel
                );

我收到 NotSupportedException：

The expression tree is not supported: {document}{RemoteBoard}{apps}.SingleOrDefault(app => (app.appname == "eACM")).objects.SingleOrDefault(model => (model.name == "tag")).config_docs

我感觉我使用 LINQ 关键字的方式不对，或者 MongoDb 不支持的方式，但很难准确判断问题出在哪里。

我无法对堆栈跟踪进行任何处理：

at MongoDB.Driver.Linq.Processors.EmbeddedPipeline.EmbeddedPipelineBinder.BindNonMethodCall(Expression node) at MongoDB.Driver.Linq.Processors.PipelineBinderBase1.BindPipeline(Expression node) at MongoDB.Driver.Linq.Processors.PipelineBinderBase1.BindMethodCall(MethodCallExpression node) at MongoDB.Driver.Linq.Processors.EmbeddedPipeline.EmbeddedPipelineBinder.Bind(Expression node, IBindingContext parent) at MongoDB.Driver.Linq.Processors.SerializationBinder.VisitMethodCall(MethodCallExpression node) at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor) at MongoDB.Driver.Linq.Processors.SerializationBinder.Visit(Expression node) at System.Linq.Expressions.ExpressionVisitor.VisitBinary(BinaryExpression node) at MongoDB.Driver.Linq.Processors.SerializationBinder.VisitBinary(BinaryExpression node) at System.Linq.Expressions.BinaryExpression.Accept(ExpressionVisitor visitor) at MongoDB.Driver.Linq.Processors.SerializationBinder.Visit(Expression node) at MongoDB.Driver.Linq.Translators.PredicateTranslator.Translate[TDocument](Expression1 predicate, IBsonSerializer1 parameterSerializer, IBsonSerializerRegistry serializerRegistry) at MongoDB.Driver.MongoCollectionImpl1.ConvertWriteModelToWriteRequest(WriteModel1 model, Int32 index) at System.Linq.Enumerable.SelectIterator[TSource,TResult](IEnumerable1 source, Func3 selector)+MoveNext() at System.Collections.Generic.List1.AddEnumerable(IEnumerable1 enumerable) at System.Linq.Enumerable.ToList[TSource](IEnumerable1 source) at MongoDB.Driver.Core.Operations.BulkMixedWriteOperation..ctor(CollectionNamespace collectionNamespace, IEnumerable1 requests, MessageEncoderSettings messageEncoderSettings) at MongoDB.Driver.MongoCollectionImpl1.CreateBulkWriteOperation(IEnumerable1 requests, BulkWriteOptions options) at MongoDB.Driver.MongoCollectionImpl1.BulkWriteAsync(IClientSessionHandle session, IEnumerable1 requests, BulkWriteOptions options, CancellationToken cancellationToken) at MongoDB.Driver.MongoCollectionImpl1.UsingImplicitSessionAsync[TResult](Func2 funcAsync, CancellationToken cancellationToken) at MongoDB.Driver.MongoCollectionBase1.UpdateOneAsync(FilterDefinition1 filter, UpdateDefinition1 update, UpdateOptions options, Func3 bulkWriteAsync) at WebApplication.Services.ConcreteDatabase.UpdateDocument[T](String sCollectionName, Expression1 filter, UpdateDefinition1 update, Boolean bUpsert, CancellationToken cancellationToken) in C:\GIT\app-manager\APIMM\ServerLevelConfiguration\WebApplication\Services\ConcreteDatabase.cs:line 131 at WebApplication.Services.SyncBoardDatabaseBackgroundService.UpdateDbOnSyncServerToBoardUpdate(CancellationToken cancel, BsonDocument bsonDocConfigurationToUpdate, DateTime dtUpdated, String sId, Int32 iObjectId, String sAppName, String sModelName) in C:\GIT\app-manager\APIMM\ServerLevelConfiguration\WebApplication\Services\SyncBoardDatabaseBackgroundService.cs:line 353

型号类:

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

    [BsonElement]
    public NodeBoardRemoteModel RemoteBoard { get; set; }
}

public class NodeBoardRemoteModel
{
    [BsonElement]
    public List<NodeBoardAppModel> apps { get; set; }
}

public class NodeBoardAppModel
{
    [BsonElement]
    public string appname { get; set; }

    [BsonElement]
    public List<NodeBoardObjectModel> objects { get; set; }
}

public class NodeBoardObjectModel
{
    [BsonElement]
    public string name { get; set; }

    [BsonElement]
    public List<NodeBoardObjectConfigurationModel> config_docs { get; set; }
}

public class NodeBoardObjectConfigurationModel
{
    [BsonElement]
    public BsonDocument config_doc { get; set; }

    [BsonElement]
    public DateTime config_dt { get; set; }

    [BsonElement]
    public int config_id { get; set; }
}

Answer 1

当您尝试构建 Update 语句时，问题就开始了。正如您可能知道的那样，作为索引传递的 -1 将是 to the $ positional operator. The documentation 表示

The positional $ operator cannot be used for queries which traverse more than one array, such as queries that traverse arrays nested within other arrays, because the replacement for the $ placeholder is a single value

此外，您正在尝试使用 SingleOrDefault 构建过滤条件，而 .NET MongoDB 驱动程序无法将其转换为任何 MongoDB 查询语法运算符。

如何解决？

您可以尝试使用 positional filtered operator 语法而不是使用位置运算符。

var filter = Builders<NodeBoardModel>.Filter.Eq(f => f.Id, sId);
var update = Builders<NodeBoardModel>.Update.Set("RemoteBoard.apps.$[app].objects.$[object].config_docs.$[configdoc].config_dt", dtUpdated);

var arrayFilters = new List<ArrayFilterDefinition>();
ArrayFilterDefinition<BsonDocument> appFilter = new BsonDocument("app.appname", new BsonDocument("$eq", sAppName));
ArrayFilterDefinition<BsonDocument> objectFilter = new BsonDocument("object.name", new BsonDocument("$eq", sModelName));
ArrayFilterDefinition<BsonDocument> configDocFilter = new BsonDocument("configdoc.config_id", new BsonDocument("$eq", iObjectId));

arrayFilters.AddRange(new[] { appFilter, objectFilter, configDocFilter });

var updateOptions = new UpdateOptions { ArrayFilters = arrayFilters };

var res = Col.UpdateOne(filter, update, updateOptions);

UpdateOneAsync 不支持表达式树

Expression tree is not supported on UpdateOneAsync

c#

linq

mongodb

mongodb-.net-driver