How to use $match (multiple conditions) and $group in Mongodb - mongodb

Question

have list of records with the following fields - postBalance, agentId, createdAt, type. I want to filter by “type” and date. After this is done I want to get the $last postBalance for each agent based on the filter and sum up the postBalance. I have been struggling with this using this query
db.transaction.aggregate(
[{ $match: {
$and: [ {
createdAt: { $gte: ISODate('2022-09-15'), $lt:
('2022-09-16') } },
{ type: "CASH_OUT"}]}},
{
$group:
{
_id: {createdAt: {$last: "$createdAt"}},
totalAmount: { $sum: "$postBalance" },
}
}
]
)
An empty array is returned with this query and there are data in the collection.
Below are samples of the documents
{
"_id": {
"$oid": "6334cefd0048787d5535ff16"
},
"type": "CASH_OUT",
"postBalance": {
"$numberDecimal": "23287.625"
},
"createdAt": {
"$date": {
"$numberLong": "1664405245000"
}
},
}
{
"_id": {
"$oid": "6334d438c1ab8a577677cbf3"
},
"userID": {
"$oid": "62f27bc29f51747015fdb941"
},
"aggregatorID": "0000116",
"transactionFee": {
"$numberDecimal": "0.0"
},
"type": "AIRTIME_VTU",
"postBalance": {
"$numberDecimal": "2114.675"
},
"walletHistoryID": 613266,
"walletID": 1720,
"walletActionAt": {
"$date": {
"$numberLong": "1664406584000"
}
},
{
"type": "FUNDS_TRANSFER",
"postBalance": {
"$numberDecimal": "36566.39"
},
"createdAt": {
"$date": {
"$numberLong": "1664407090000"
}
}
}
This is the output I am expecting
{
"date" : 2022-10-09,
"CASHOUT ": 897663,088,
"FUNDS_TRANSFER": 8900877,
"AIRTIME_VTU": 8890000
}
How can my query be aggregated to get this? Thanks

Answer 1

It look like you want something like:
db.collection.aggregate([
{$match: {
createdAt: {
$gte: ISODate("2022-09-15T00:00:00.000Z"),
$lt: ISODate("2022-09-30T00:00:00.000Z")
}
}
},
{$group: {
_id: "$type",
createdAt: {$first: "$createdAt"},
totalAmount: {$sum: "$postBalance"}
}
},
{$group: {
_id: 0,
createdAt: {$first: "$createdAt"},
data: {$push: {k: "$_id", v: "$totalAmount"}}
}
},
{$project: {
data: {$arrayToObject: "$data"},
createdAt: 1,
_id: 0
}
},
{$set: {"data.date": "$createdAt"}},
{$replaceRoot: {newRoot: "$data"}}
])
See how it works on the playground example