$graphLookup return void array - node.js

Question

I have below collection:
[{
"_id": "60035d0a1599912a5c814e58",
"idUsuario": "600365521599912a5c814e5e",
"parentNode": "",
"piernaPadre": "",
"estado": "1"
},
{
"_id": "6003827b06b4423c9ca7e6aa",
"idUsuario": "60036e53dda7df34749ebf3a",
"parentNode": "60035d0a1599912a5c814e58",
"piernaPadre": "d",
"estado": 1
},
{
"_id": "60038c92ea7d593fe029cc0f",
"idUsuario": "600382a506b4423c9ca7e6ab",
"parentNode": "6003827b06b4423c9ca7e6aa",
"piernaPadre": "d",
"estado": 1
}]
I need to get the descendants of a node, I'm trying with $graphLookup,
$graphLookup: {
from: "nodoModel",
startWith: "$_id",
connectFromField: "_id",
connectToField: "parentNode",
as: "arrayDes"
}
but does not work, the return is void. Is there a mistake?
Thanks.
EDIT 1
Now I can get a result when try to get de ancestors of a node:
$graphLookup: {
from: "nodos",
startWith: "$_id",
connectFromField: "_id",
connectToField: "nodoPadre",
as: "padre"
}
Whit below result:
[
{
_id: 60035d0a1599912a5c814e58,
idUsuario: '600365521599912a5c814e5e',
parentNode: '',
piernaPadre: '',
estado: '1',
padre: [ [Object] ]
},
{
_id: 6004589436a40941f48121f8,
idUsuario: '600365e9ccf1e51b2cab341f',
parentNode: '60035d0a1599912a5c814e58',
piernaPadre: 'd',
estado: 1,
createdAt: 2021-01-17T15:32:36.986Z,
updatedAt: 2021-01-17T15:32:36.986Z,
__v: 0,
padre: [ [Object] ]
},
{
_id: 6004592936a40941f48121fa,
idUsuario: '6004591536a40941f48121f9',
parentNode: '6004589436a40941f48121f8',
piernaPadre: 'd',
estado: 1,
createdAt: 2021-01-17T15:35:05.626Z,
updatedAt: 2021-01-17T15:35:05.626Z,
__v: 0,
padre: [ [Object] ]
}
]
But I need to get the descendants not the ancestors
EDIT 2
(in the original model parentNode is named nodoPadre)
It is a screenshot of my code:
and that is the console.log:
arrayDes is a void array. I'm using mongoose, maybe it is related with the problem?
EDIT 3
I'm trying to change type of nodoPadre to objectId

Answer 1

Try query to get descendants,
$match put condition
$grouphLookup same as yours
{ $match: { nodoPadre: "" } },
{
$graphLookup: {
from: "collection",
startWith: "$_id",
connectFromField: "_id",
connectToField: "nodoPadre",
as: "arrayDes"
}
}
Playground
For your Second Edit:
Update nodoPadre type to object id type in all documents, and change type in schema to type: mongoose.Types.ObjectId
nodoPadre: {
type: mongoose.Types.ObjectId,
required: [false, '2'],
index: true
}

Answer 2

I had the same issue and finally I resolved it by chnaging the collection name to small letters and it should be plural based on mongodb . Here is my details
Mongoose schema:
const fileFolderSchema = new Schema({
name: String,
parentFolder: {type: Mongoose.Types.ObjectId, ref: "FileFolder"},
path: String,
metadata: {
type: metaDataSchema
}
}, { id: false }).set('toJSON', {
virtuals: true
});
export const FileFolder = Mongoose.model('FileFolder', fileFolderSchema);
Nodejs Method:
folder_tree_structure: async(ctx:any) => {
try {
let treeStructure = await FileFolder.aggregate([
{
$match: {
parentFolder: {
$exists: true
}
}
},
{
$graphLookup: {
from: 'filefolders', // here your collection name is always small letters and plural
startWith: '$_id',
connectFromField: 'parentFolder',
connectToField: 'parentFolder',
maxDepth: 1,
depthField: 'depth',
as: 'TreeResult'
}
}
]);
console.log('tree structure',treeStructure )
ctx.status = 200;
ctx.body = treeStructure;
} catch (err) {
ctx.status = 400;
ctx.body = 'Not found'
}
}
My Nodejs response:
[
{
"_id": "636cd1d2692344da47f3e2f0",
"name": "Folder2",
"path": "files/Folder2",
"metadata": {
"version": 1,
"created_by": "user-1",
"created_on": "2022-11-10T10:26:26.828Z",
"timeout": -1
},
"__v": 0,
"parentFolder": "636cd213692344da47f3e2f5",
"TreeResult": [
{
"_id": "636cd238692344da47f3e301",
"name": "Folder3",
"path": "files/Folder3",
"metadata": {
"version": 1,
"created_by": "user-1",
"created_on": "2022-11-10T10:28:08.655Z",
"timeout": -1
},
"__v": 0,
"parentFolder": "636cd1d2692344da47f3e2f0",
"depth": 0
},
{
"_id": "636d075874867ade3d3c3224",
"name": "images",
"path": "files/images",
"metadata": {
"version": 1,
"created_by": "user-1",
"created_on": "2022-11-10T14:14:48.871Z",
"timeout": -1
},
"__v": 0,
"parentFolder": "636cd1d2692344da47f3e2f0",
"depth": 0
}
]
},
{
"_id": "636cd213692344da47f3e2f5",
"name": "Folder1",
"path": "files/Folder1",
"metadata": {
"version": 1,
"created_by": "user-1",
"created_on": "2022-11-10T10:27:31.600Z",
"timeout": -1
},
"__v": 0,
"parentFolder": "636cd213692344da47f3e2f5",
"TreeResult": [
{
"_id": "636cd213692344da47f3e2f5",
"name": "Folder1",
"path": "files/Folder1",
"metadata": {
"version": 1,
"created_by": "user-1",
"created_on": "2022-11-10T10:27:31.600Z",
"timeout": -1
},
"__v": 0,
"parentFolder": "636cd213692344da47f3e2f5",
"depth": 0
},
{
"_id": "636cd1d2692344da47f3e2f0",
"name": "Folder2",
"path": "files/Folder2",
"metadata": {
"version": 1,
"created_by": "user-1",
"created_on": "2022-11-10T10:26:26.828Z",
"timeout": -1
},
"__v": 0,
"parentFolder": "636cd213692344da47f3e2f5",
"depth": 0
},
{
"_id": "636ce2452e97522606b14b23",
"name": "images",
"path": "files/images",
"metadata": {
"version": 1,
"created_by": "user-1",
"created_on": "2022-11-10T11:36:37.691Z",
"timeout": -1
},
"__v": 0,
"parentFolder": "636cd213692344da47f3e2f5",
"depth": 0
}
]
},
{
"_id": "636cd238692344da47f3e301",
"name": "Folder3",
"path": "files/Folder3",
"metadata": {
"version": 1,
"created_by": "user-1",
"created_on": "2022-11-10T10:28:08.655Z",
"timeout": -1
},
"__v": 0,
"parentFolder": "636cd1d2692344da47f3e2f0",
"TreeResult": []
},
{
"_id": "636ce2452e97522606b14b23",
"name": "images",
"path": "files/images",
"metadata": {
"version": 1,
"created_by": "user-1",
"created_on": "2022-11-10T11:36:37.691Z",
"timeout": -1
},
"__v": 0,
"parentFolder": "636cd213692344da47f3e2f5",
"TreeResult": []
},
{
"_id": "636d075874867ade3d3c3224",
"name": "images",
"path": "files/images",
"metadata": {
"version": 1,
"created_by": "user-1",
"created_on": "2022-11-10T14:14:48.871Z",
"timeout": -1
},
"__v": 0,
"parentFolder": "636cd1d2692344da47f3e2f0",
"TreeResult": []
}
]
Here is mongo play ground link:
https://mongoplayground.net/p/M4pEB34Ozib