How to get only specific nested object from MongoDB collection where uuid is used as key - mongodb

Question

I only want this matched object in query result, by querying uuid "630c260e333c41549c43cae5f8e626d5":
{
"enableAnnotations": false,
"enableMultipleFilesUpload": true,
"enableWorkflows": true,
"formSectionID": "a9bcde7f8fc14e519965a655d9574fb7",
"isThumbnailField": false,
"label": "WD multi upload Ttl in Dup Section DW",
"publishToFolder": false,
"publishWhenApproved": false,
"type": "upload",
"uuid": "630c260e333c41549c43cae5f8e626d5"
}
from the following Collection document:
[{
"_id": "07672b703cc44ce6887159984911dd6e",
"createTime": "2022-06-21T12:08:00Z",
"creator": "75e5d59fa1be0f932bff8407536730d0",
"defination": {
"fields": {
"a9bcde7f8fc14e519965a655d9574fb7": [
{
"enableAnnotations": false,
"enableMultipleFilesUpload": true,
"enableWorkflows": true,
"formSectionID": "a9bcde7f8fc14e519965a655d9574fb7",
"isThumbnailField": false,
"label": "WD multi upload Ttl in Dup Section DW",
"publishToFolder": false,
"publishWhenApproved": false,
"type": "upload",
"uuid": "630c260e333c41549c43cae5f8e626d5"
},
{
"enableAnnotations": false,
"enableMultipleFilesUpload": false,
"formSectionID": "a9bcde7f8fc14e519965a655d9574fb7",
"isThumbnailField": false,
"label": "WD single upload in Dup section DW",
"publishToFolder": false,
"type": "upload",
"uuid": "1aecb33709434d9b9a0cb455c67e2295"
}
],
"eda3ce9883a14b948eae5b053f720227": [
{
"enableAnnotations": false,
"enableMultipleFilesUpload": true,
"enableWorkflows": true,
"formSectionID": "eda3ce9883a14b948eae5b053f720227",
"isThumbnailField": false,
"label": "WD upload multi",
"publishToFolder": false,
"publishWhenApproved": false,
"type": "upload",
"uuid": "e88a097621cc44c4bb440902006f5a12"
},
{
"formSectionID": "eda3ce9883a14b948eae5b053f720227",
"label": "WD Txt Fld Ttl",
"type": "text",
"uuid": "e1bf361509364718b9d52e65cbc292de",
},
{
"enableAnnotations": false,
"enableMultipleFilesUpload": true,
"enableWorkflows": true,
"formSectionID": "eda3ce9883a14b948eae5b053f720227",
"isThumbnailField": false,
"label": "WD 2nd-multi-upload",
"publishToFolder": false,
"publishWhenApproved": false,
"type": "upload",
"uuid": "fbee1d1adf224712a90f3f37b8395aa0"
},
{
"enableAnnotations": true,
"enableMultipleFilesUpload": false,
"formSectionID": "eda3ce9883a14b948eae5b053f720227",
"isThumbnailField": false,
"label": "WD single upload Ttl DW",
"publishToFolder": false,
"type": "upload",
"uuid": "5504ce66d1bc4f659eefed4df4e73b99",
}
]
},
"sections": {
"291b58eddee04a05bd8e7d80d99241b9": [
{
"uuid": "eda3ce9883a14b948eae5b053f720227"
},
{
"uuid": "a9bcde7f8fc14e519965a655d9574fb7"
}
]
},
"tabs": [
{
"uuid": "291b58eddee04a05bd8e7d80d99241b9"
}
]
}
}]
After some research, I used the query: (by referring how to select value if key is uuid in mongodb)
db.collection.aggregate([
{
"$set": {
"fields": {
"$objectToArray": "$defination.fields"
}
}
},
{
"$unwind": "$fields"
},
{
"$match": {
"fields.v.uuid": "630c260e333c41549c43cae5f8e626d5",
"fields.v.enableWorkflows": true,
"fields.v.enableMultipleFilesUpload": true,
"fields.v.type": "upload"
}
},
{
"$group": {
"_id": "$_id",
"fields": {
"$push": "$fields"
}
}
},
{
"$set": {
"fields": {
"$arrayToObject": "$fields"
}
}
}
])
and I got the result:
[
{
"_id": "07672b703cc44ce6887159984911dd6e",
"fields": {
"a9bcde7f8fc14e519965a655d9574fb7": [
{
"enableAnnotations": false,
"enableMultipleFilesUpload": true,
"enableWorkflows": true,
"formSectionID": "a9bcde7f8fc14e519965a655d9574fb7",
"isThumbnailField": false,
"label": "WD multi upload Ttl in Dup Section DW",
"publishToFolder": false,
"publishWhenApproved": false,
"type": "upload",
"uuid": "630c260e333c41549c43cae5f8e626d5"
},
{
"enableAnnotations": false,
"enableMultipleFilesUpload": false,
"formSectionID": "a9bcde7f8fc14e519965a655d9574fb7",
"isThumbnailField": false,
"label": "WD single upload in Dup section DW",
"publishToFolder": false,
"type": "upload",
"uuid": "1aecb33709434d9b9a0cb455c67e2295"
}
]
}
}
]
But it contains extra sibling objects.
I tried the answer from post but it doesn't work: How can I get only specific object from nested array mongodb

Answer 1

One option to drill down is using $reduce with $filter, but first we need known keys, hence the $objectToArray which you already have:
db.collection.aggregate([
{$project: {fields: {$objectToArray: "$defination.fields"}}},
{$project: {res: {
$first: {
$reduce: {
input: "$fields",
initialValue: [],
in: {$concatArrays: [
"$$value",
{$filter: {
input: "$$this.v",
as: "inner",
cond: {
$eq: [
"$$inner.uuid",
"630c260e333c41549c43cae5f8e626d5"
]
}
}
}
]
}
}
}
}
}
},
{$replaceRoot: {newRoot: {$ifNull: ["$res", {}]}}}
])
See how it works on the playground example