MongoDB $graphLookup get children all levels deep - nested result

[Kyriakos Mandalas]

As presented in https://www.slideshare.net/mongodb/webinar-working-with-graph-data-in-mongodb, slide 50 it is possible to use $graphLookup on a View in order to get a 2 levels deep tree-structure in nested format.

I have a MongoDB collection with tree nodes as documents with the following format:

{ "_id" : { "$oid" : "5b1a952361c6fa3418a15660" }, 
"nodeId" : 23978995, 
"name" : "settings", 
"type" : "Node",
"parentId" : [ 23978893, 23979072, 23979081 ] }

I have created a View like:

db.createView("treeView", "node", [
{
 $graphLookup: {
    from: "node",
    startWith: "$nodeId",
    connectFromField: "nodeId",
    connectToField: "parentId",
    maxDepth: 0,
    as: "children"
 }
}
]);

And I execute graph lookups like:

db.node.aggregate([ 
{ $match: {"nodeId": 23978786 } },
{
 $graphLookup: {
    from: "treeView",
    startWith: "$nodeId",
    connectFromField: "nodeId",
    connectToField: "parentId",
    maxDepth: 0,
    as: "children"
 }
}
]);

My question is how can I get the whole hierarchy, all levels deep?

[Stephen Steneker]

Hi Kyriakos,

I noticed this question has also been posted (and answered) on Stack Overflow: https://stackoverflow.com/q/50767930/1388319.

Regards,

Stennie