nodejs + mongodb error exception: FieldPath 'progress' doesn't start with $ - node.js

Question

I'm trying to modify the second pipeline from this query (which I got from here nodejs + mongoose - query aggregate
db.todos.aggregate([
{
"$group": {
"_id": "$pic",
"open_count": {
"$sum": {
"$cond": [ { "$eq": [ "$status", "open" ] }, 1, 0 ]
}
},
"progress_count": {
"$sum": {
"$cond": [ { "$eq": [ "$status", "progress" ] }, 1, 0 ]
}
},
"done_count": {
"$sum": {
"$cond": [ { "$eq": [ "$status", "done" ] }, 1, 0 ]
}
},
"archive_count": {
"$sum": {
"$cond": [ { "$eq": [ "$status", "archive" ] }, 1, 0 ]
}
}
}
},
{
"$group": {
"_id": "$_id",
"detail": {
"$push": {
"name": "open",
"$todos": "$open_count"
},
"$push": {
"name": "progress",
"$todos": "$progress_count"
},
"$push": {
"name": "done",
"$todos": "$done_count"
},
"$push": {
"name": "archive",
"$todos": "$archive_count"
}
}
}
},
{
"$project": {
"_id": 0, "pic": "$_id", "detail": 1
}
}
])
I want this kind of JSON structure so I can put it on google chart, which the format is like this:
[
{
"pic": "A",
"detail": [
{
"name": "open",
"todos": 2
},
{
"name": "progress",
"todos": 1
},
{
"name": "done",
"todos": 8
},
{
"name": "archive",
"todos": 20
}
],
"pic": "B",
"detail": [
{
"name": "open",
"todos": 5
},
{
"name": "progress",
"todos": 2
},
{
"name": "done",
"todos": 5
},
{
"name": "archive",
"todos": 10
}
],
}
]
But I got this error
exception: FieldPath 'progress' doesn't start with $

Answer 1

Try with this aggregation query:
db.todos.aggregate([
{
"$group": {
"_id": {
"pic": "$pic",
"name": "$status"
},
"todos": {
"$sum": 1
}
}
},
{
"$project": {
"_id": 0,
"pic": "$_id.pic",
"detail": {
"name": "$_id.name",
"todos": "$todos"
}
}
},
{
"$group": {
"_id": "$pic",
"detail": {
"$push": "$detail"
}
}
},
{
"$project": {
"_id": 0, "pic": "$_id", "detail": 1
}
}])