Conditionally Count Value from Array into New Field - mongodb

Question

Consider the following data:
{
"_id" : ObjectId("592ffb3d257acc76fc0eecd7"),
"primaryProcessName" : "BI",
"dateTimeStamp" : ISODate("2017-06-01T11:32:12.834+0000"),
"tag" : [
{
"key" : "processname",
"value" : "NEUpdateService",
"value_original" : "NEUpdateService"
},
{
"key" : "processstageid",
"value" : "inprocess",
"value_original" : "InProcess"
},
]
}
{
"_id" : ObjectId("592ffb3d257acc76fc0eecdd"),
"primaryProcessName" : "BI",
"dateTimeStamp" : ISODate("2017-06-01T11:32:13.345+0000"),
"tag" : [
{
"key" : "processname",
"value" : "CommissionPaymentSend",
"value_original" : "CommissionPaymentSend"
},
{
"key" : "processstageid",
"value" : "faulted",
"value_original" : "Faulted"
},
]
}
{
"_id" : ObjectId("592ffb3d257acc76fc0eece4"),
"primaryProcessName" : "BI",
"dateTimeStamp" : ISODate("2017-06-01T11:32:13.745+0000"),
"tag" : [
{
"key" : "processname",
"value" : "commonbusinessintegratorservice",
"value_original" : "CommonBusinessIntegratorService"
},
{
"key" : "processstageid",
"value" : "inprocess",
"value_original" : "InProcess"
},
]
}
{
"_id" : ObjectId("592ffb3d257acc76fc0eecea"),
"primaryProcessName" : "BI",
"dateTimeStamp" : ISODate("2017-06-01T11:32:13.876+0000"),
"tag" : [
{
"key" : "processname",
"value" : "commonbusinessintegratorservice",
"value_original" : "CommonBusinessIntegratorService"
},
{
"key" : "processstageid",
"value" : "inprocess",
"value_original" : "InProcess"
},
]
}
{
"_id" : ObjectId("592ffb3e257acc76fc0eecf1"),
"primaryProcessName" : "BI",
"dateTimeStamp" : ISODate("2017-06-01T11:32:14.193+0000"),
"tag" : [
{
"key" : "processname",
"value" : "SmartComplianceMessenger",
"value_original" : "SmartComplianceMessenger"
},
{
"key" : "processstageid",
"value" : "complete",
"value_original" : "Complete"
},
]
}
I am trying to write a query to aggregate this data to show in the following format:
{
"Total" : 1982, "InProcess" : 991, "Complete" : 991, "Faulted" : 0,
"name" : "SmartComplianceMessenger",
"displayName" : "SmartComplianceMessenger",
"drillDownUrl" : "process/forprimary/name/SmartComplianceMessenger"
},
{
"Total" : 122333, "InProcess" : 56375, "Complete" : 54856, "Faulted" : 11102,
"name" : "NEUpdateService",
"displayName" : "NEUpdateService",
"drillDownUrl" : "process/forprimary/name/NEUpdateService"
},
....
This is what I have so far:
db.ActivityNotice.aggregate([
{$match: {
dateTimeStamp: {
$gte: ISODate("2017-06-01T11:00:00.000Z")
, $lt: ISODate("2017-06-01T11:45:00.000Z")
}
}},
{$group :
{
_id: {process: "$primaryProcessName"} //, status:"$processStageId"
, Total:{$sum:1}
, InProcess: {$sum:0}// { $sum: {$cond: [{$eq: ["$processStageId","InProcess"]},1,0]}}
, Complete: {$sum:0} // { $sum: {$cond: [{$eq: ["$processStageId","Complete"]},1,0]}}
, Faulted: {$sum:0} // { $sum: {$cond: [{$eq: ["$processStageId","Faulted"]},1,0]}}
, Test: { $sum: {$cond: [{$eq: ["tag.key","processstageid"]},1,0]}}
}},
{$project: {
_id: 0,
name: "$_id.process", displayName: "$_id.process",
drillDownUrl: { $concat: [ "process/forprimary/name/", "$_id.process" ] },
Total: 1, InProcess: 1 , Complete: 1, Faulted: 1, Test: 1
}}
])
The challenge I am facing is selecting the value for the "processname" key from tags into a new field, called processName and the value for "processtageid" into a new field so I can do the sum on those values.
Any help would be greatly appreciated.

Answer 1

You want $filter and $size for the most efficient way:
{ "$group": {
"_id": "$primaryProcessName",
"Total": { "$sum": 1 },
"InProcess": {
"$sum": {
"$size": {
"$filter": {
"input": "$tag",
"as": "t",
"cond": {
"$and": [
{ "$eq": [ "$$t.key", "processstageid" ] },
{ "$eq": [ "$$t.value","inprocess"] }
]
}
}
}
}
},
"Complete": {
"$sum": {
"$size": {
"$filter": {
"input": "$tag",
"as": "t",
"cond": {
"$and": [
{ "$eq": [ "$$t.key", "processstageid" ] },
{ "$eq": [ "$$t.value","complete"] }
]
}
}
}
}
},
"Faulted": {
"$sum": {
"$size": {
"$filter": {
"input": "$tag",
"as": "t",
"cond": {
"$and": [
{ "$eq": [ "$$t.key", "processstageid" ] },
{ "$eq": [ "$$t.value","faulted"] }
]
}
}
}
}
}
}}
$filter has it's own condition for which we can use $and to match the multiple conditions of different properties of the array element. This reduces the array to only the entries that match, where you can then take the $size