我正在尝试使用新的 MongoDB v3.4 $graphLookup 聚合管道元素。我的数据“节点”可以有 0、1 或多个父节点。每个节点还可以有 0 个、1 个或多个子节点。我想使用 $graphLookup 生成以下输出：
{"parentNodeKey": undefined, "parentLabel": undefined, "nodeKey": 1, "nodeLabel": "Node 1"},
{"parentNodeKey": 1, "parentLabel": "Node 1", "nodeKey": 11, "nodeLabel": "Node 1.1"},
{"parentNodeKey": 1, "parentLabel": "Node 1", "nodeKey": 12, "nodeLabel": "Node 1.2"},
{"parentNodeKey": 1, "parentLabel": "Node 1", "nodeKey": 13, "nodeLabel": "Node 1.3"},
{"parentNodeKey": 1, "parentLabel": "Node 1", "nodeKey": 31, "nodeLabel": "Node 3.1"},
{"parentNodeKey": 11, "parentLabel": "Node 1.1", "nodeKey": 111, "nodeLabel": "Node 1.1.1"},
{"parentNodeKey": 11, "parentLabel": "Node 1.1", "nodeKey": 112, "nodeLabel": "Node …