Solusi di bawah ini kurang lebih sama dengan salah satu jawaban saya sebelumnya sehingga Anda bisa mendapatkan penjelasan menyeluruh di sini
db.projects.aggregate([
{
$graphLookup: {
from: "projects",
startWith: "$_id",
connectFromField: "_id",
connectToField: "parent",
as: "children",
maxDepth: 4,
depthField: "level"
}
},
{
$unwind: "$children"
},
{
$sort: { "children.level": -1 }
},
{
$group: {
_id: "$_id",
children: { $push: "$children" }
}
},
{
$addFields: {
children: {
$reduce: {
input: "$children",
initialValue: {
currentLevel: -1,
currentLevelProjects: [],
previousLevelProjects: []
},
in: {
$let: {
vars: {
prev: {
$cond: [
{ $eq: [ "$$value.currentLevel", "$$this.level" ] },
"$$value.previousLevelProjects",
"$$value.currentLevelProjects"
]
},
current: {
$cond: [
{ $eq: [ "$$value.currentLevel", "$$this.level" ] },
"$$value.currentLevelProjects",
[]
]
}
},
in: {
currentLevel: "$$this.level",
previousLevelProjects: "$$prev",
currentLevelProjects: {
$concatArrays: [
"$$current",
[
{ $mergeObjects: [
"$$this",
{ children: { $filter: { input: "$$prev", as: "e", cond: { $eq: [ "$$e.parent", "$$this._id" ] } } } }
] }
]
]
}
}
}
}
}
}
}
},
{
$addFields: { children: "$children.currentLevelProjects" }
},
{
$match: {
_id: "1"
}
}
])
Tahap terakhir adalah penyaringan sehingga Anda bisa mendapatkan data untuk semua tingkat kedalaman di sini.
