AggregateGraphLookupOptions mongo GraphLookup 集

Question

如何为 GraphLookup 设置选项， 现在设置选项我不能设置通用类型。

  var options = new **AggregateGraphLookupOptions<BsonDocument, BsonDocument, BsonDocument>**
            {
                MaxDepth = 2,
            };

var ss1 = aggregate.GraphLookup(this.EntitiesCol, "To", "From", startField, "destinations", **options**);

在 ss1 之后我用于匹配和分组...

错误：

严重性代码描述项目文件行抑制状态 错误 CS0411 方法的类型参数 'IAggregateFluent.GraphLookup（IMongoCollection，FieldDefinition，FieldDefinition， 聚合表达式定义， 字段定义，字段定义， AggregateGraphLookupOptions)' 不能 从用法推断。尝试指定类型参数 明确地。 Abc.eStepControl.Infrastructure F:\ABC\eStepControl\eStepControl\EngineGit\dev\eStepControl.Engine\src\eStepControl.Infrastructure\Repositories\EdgesRepository.cs 684 活动

Answer 1

使用 AppendStage() 方法添加 graphLookup 阶段如下：

var graphLookupStage = new BsonDocument("$graphLookup",
                        new BsonDocument
                            {
                                    { "from", "someCollection" },
                                    { "startWith", "$reportsTo" },
                                    { "connectFromField", "reportsTo"},
                                    { "connectToField",  "name" },
                                    { "as", "reportingHierarchy" },
                                    { "maxDepth", 1 },
                                    { "depthField", "depthField" } //optional
                        });
var result = collection.Aggregate().AppendStage<BsonDocument>(graphLookupStage);