Multiple condition in group by mongodb - mongodb

Question

I have data like this in a database:
{
"_id" : ObjectId("5ec4e40a7c89c96c7c3818f0"),
"lob" : "DIGITAL_STORE",
"paymentMode" : "NET_BANKING",
"pgStatus" : "PG_SUCCESS",
"createdAt" : ISODate("2020-05-20T08:02:18.566Z"),
"updatedAt" : ISODate("2020-07-22T18:57:29.915Z"),
"updatedBy" : "ONLINE_CHANNEL",
"_class" : "com.airtel.payments.pg.commons.persistence.PgTransactionDetails"
},
{
"_id" : ObjectId("5ec4e40a7c89c96c7c3818f0"),
"lob" : "DIGITAL_STORE",
"paymentMode" : "NET_BANKING",
"pgStatus" : "PG_FAILED",
"createdAt" : ISODate("2020-05-20T08:02:18.566Z"),
"updatedAt" : ISODate("2020-07-22T18:57:29.915Z"),
"updatedBy" : "ONLINE_CHANNEL",
"_class" : "com.airtel.payments.pg.commons.persistence.PgTransactionDetails"
}
I need to get data from mongodb where I can fetch count of success and failure in one document grouped by LOB & Payment mode.
I tried something like this, but lob and payment mode segregation not coming.
db.getCollection('transactionDetails').aggregate([
{$project: {
Success: {$cond: [{$eq: ["$pgStatus", "PG_SUCCESS" ]}, 1, 0]},
Failed: {$cond: [{$eq: ["$pgStatus", "PG_FAILED"]}, 1, 0]}
}},
{$group: {
_id: {Lob:"$lob",Mode:"$paymentMode"},
Success: {$sum: "$Success"},
Failed: {$sum: "$Failed"}
}}
]);
I can do this separately but not able to get in single document both count of success and failure transaction.

Answer 1

Because you have used $project and you have projected one field only and other fields are no longer available for next pipeline,
You can add other fields in $project or you can use $addFields instead of $project,
Playground
or you can try inside all operations in $group,
db.getCollection('transactionDetails').aggregate([
{
$group: {
_id: { Lob: "$lob", Mode: "$paymentMode" },
Success: {
$sum: { $cond: [{ $eq: ["$pgStatus", "PG_SUCCESS"] }, 1, 0] }
},
Failed: {
$sum: { $cond: [{ $eq: ["$pgStatus", "PG_FAILED"] }, 1, 0] }
}
}
}
])
Playground