How to fetch all fields of parent document? - mongodb

Question

I have tried to fetch all fields of parent document using $group but it send only specific fields.
Another Question. How to fetch all fields of parent document using '$project'?
Collection "Opportunity"
Document #1
{
"_id" : ObjectId("5c42b737cd94891a57fbf33e"),
"accountId" : [
ObjectId("5c29f198b248d845931a1830"),
ObjectId("5c29f198b248d845931a1831"),
]
"name" : "OppNewTest01",
"value" : 10000,
"status" : "open",
}
Collection "Account"
Document #1
{
"_id" : ObjectId("5c29f198b248d845931a1830"),
"name" : "MyTestAcc",
"phone" : "7845124578",
}
My MongoDB Query,
con.collection('opportunity').aggregate([
{
$unwind: "account"
},
{
$lookup: {
from: 'account',
localField: 'accountId',
foreignField: '_id',
as: 'accounts',
},
},
{
$unwind: '$accounts'
},
{
$group: {
"_id": "$_id",
"account": { "$push": "$accounts" }
}
},
]).toArray((err, res) => {
cbFun(res, err);
});
Output of the above query,
{
"_id" : "5c42b737cd94891a57fbf33e",
"account": [
{
"_id" : ObjectId("5c29f198b248d845931a1830"),
"name" : "MyTestAcc",
"phone" : "7845124578",
},
{
"_id" : ObjectId("5c29f198b248d845931a1831"),
"name" : "MyTestAcc1",
"phone" : "7845124579",
},
]
}
I want to below output,
{
"_id" : "5c42b737cd94891a57fbf33e",
"accountId" : [
ObjectId("5c29f198b248d845931a1830"),
ObjectId("5c29f198b248d845931a1831"),
],
"name" : "OppNewTest01",
"value" : 10000,
"status" : "open",
"account": [
{
"_id" : ObjectId("5c29f198b248d845931a1830"),
"name" : "MyTestAcc",
"phone" : "7845124578",
},
{
"_id" : ObjectId("5c29f198b248d845931a1831"),
"name" : "MyTestAcc1",
"phone" : "7845124579",
},
]
}
I have tried to fetch above output but not getting.

Answer 1

You are just losing that data when you $group, save those fields in that stage to keep them.
{
$group: {
"_id": "$_id",
"account": { "$push": "$accounts" },
value: {$first: "$value"},
status: {$first: "$status},
name: {$first: "$name"},
accountId: {$push: "$accountId},
}
}
EDIT:
[
{
$group: {
"_id": "$_id",
"accounts": { "$push": "$accounts" },
"doc": {$first: "$$ROOT"},
}
},
{
$addFields: {
"doc.accounts" :"$accounts"
}
}
]