Multiple grouping in mongodb - mongodb

Question

Sample Colloection Data :
{
"_id" : ObjectId("5f30df23243ffsdfwer3d14568bf"),
"value" : {
"busId" : 200.0,
"status" : {
"code" : {
"id" : 1.0,
"key" : "2100",
"value" : "Complete"
}
}
}
}
My Query does provides the right result, but would like to squeeze the output more by using multiple grouping or $project or any other aggregators.
mongo Query:
db.suraj_coll.aggregate([
{
$addFields: {
"value.available": {
$cond: [
{
$in: [
"$value.status.code.value",
[
"Accept",
"Complete"
]
]
},
"Approved",
"Rejected"
]
}
}
},
{
"$group": {
"_id": {
busID: "$value.busId",
status: "$value.available"
},
"subtotal": {
$sum: 1
}
}
}
])
Output:
/* 1 */
{
"_id" : {
"busID" : 200.0,
"status" : "Approved"
},
"subtotal" : 3.0
}
/* 2 */
{
"_id" : {
"busID" : 200.0,
"status" : "Rejected"
},
"subtotal" : 1.0
}
Is it possible to squeeze the output more by using any further grouping ?
Output should look like below
{
"_id" : {
"busID" : 200.0,
"Approved" : 3.0
"Rejected" : 1.0
}
}
tried with $project, by keeping the count in a doc , but couldn't place the count against Approve or Rejected.
Any suggestion would be great.

Answer 1

You can use more two pipelines after your query,
$group by busID and push status and count in status
$project to convert status array to object using $arrayToObject and merge with busID using $mergeObjects
{
$group: {
_id: "$_id.busID",
status: {
$push: {
k: "$_id.status",
v: "$subtotal"
}
}
}
},
{
$project: {
_id: {
$mergeObjects: [
{ busID: "$_id" },
{ $arrayToObject: "$status" }
]
}
}
}
Playground