Mongoose how to select certain object in embedded array - node.js

Question

I had been searching around and still not able to find the correct answer.
Basically I have the below data model in mongodb
{
"_id": {
"$oid": "565db83bcd7bef020b1bdae8"
},
"userId": {
"$oid": "5653a3267827f178214918fc"
},
"targetUser": [
{
"userId": {
"$oid": "564663a5c0aefc151625b5e2"
},
"status": "Approved",
"_id": {
"$oid": "565db83bcd7bef020b1bdaea"
}
},
{
"userId": {
"$oid": "564548249bb75c600ff94cdd"
},
"status": "Sent",
"_id": {
"$oid": "565db884cd7bef020b1bdaed"
}
}
]
},
{
"_id": {
"$oid": "565db884cd7bef020b1bdaec"
},
"userId": {
"$oid": "564548249bb75c600ff94cdd"
},
"targetUser": [
{
"userId": {
"$oid": "5653a3267827f178214918fc"
},
"status": "Pending",
"_id": {
"$oid": "565db884cd7bef020b1bdaee"
}
}
]
}
How can I only return the follow data???
{
"userId": {
"$oid": "5653a3267827f178214918fc"
},
"targetUser": [
{
"userId": {
"$oid": "564663a5c0aefc151625b5e2"
},
"status": "Approved",
"_id": {
"$oid": "565db83bcd7bef020b1bdaea"
}
},
}
I had use the below code, but the result is return null
Connection.aggregate([
{$match:{userId:'5653a3267827f178214918fc'}},
{$unwind:'$targetUser'},
{$match:{'targetUser.status':'Approved'}},
{$group:{
_id:'$_id',
targetUser:{
$push:{
status:'$targetUser.status'
}
}
}}
],function(err,connections){
console.log(connections);
console.log(err);
})
Thank you so much for the help

Answer 1

From what I see, you don't need to aggregate, a simple find with a projection parameter will return what you need.
Connection.findOne({
userId: new ObjectId("5653a3267827f178214918fc")
}).select({
targetUser: {
$elemMatch: { status: "Approved" }
}
}).exec(callback);
But if you have more fields than userId and targetUser, you'll need to add them in the second parameter like this
Connection.findOne({
userId: new ObjectId("5653a3267827f178214918fc")
}).select({
targetUser: {
$elemMatch: { status: "Approved" }
},
oneMoreField: 1,
anotherField: 1
}).exec(callback);