使用MongoDB graphLookup的AggregateFluentExtensions

Question

我一直试图使用使用AggregateFluentExtensions.的最新C#驱动程序来执行MongoDB graphLookup根据文档：该方法接收一系列参数，我无法找到使其工作的方法。

有人用过它，可以帮我举个例子吗？

这是我的聚合的json版本：

​

db.getCollection("Item").aggregate(
    [
        { 
            "$project" : {
                "itemMasterId" : 1.0, 
                "parentItemId" : 1.0
            }
        }, 
        { 
            "$graphLookup" : {
                "from" : "Item", 
                "startWith" : "$itemMasterId", 
                "connectFromField" : "itemMasterId", 
                "connectToField" : "parentItemId", 
                "as" : "ancestors", 
                "maxDepth" : 10, 
                "depthField" : "depthField", 
                "restrictSearchWithMatch" : {
                    "locationId" : 26
                }
            }
        }, 
        { 
            "$project" : {
                "itemMasterId" : 1.0, 
                "parentItemId" : 1.0, 
                "children.itemMasterId" : 1, 
                "children.parentItemId" : 1
            }
        }
    ]
);

​

谢谢!

Answer 1

(晚会晚些时候，我希望这能帮到别人。)

我已经使用了AppendStage()方法，您可以尝试如下：

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);