Mongodb How to pivot fields? - mongodb

Question

I have collection in mongo db,
so I want the fields: Ip UtilizationReports.Start UtilizationReports.CpuReports.0.ProcName UtilizationReports.CpuReports.0.MaxUsage UtilizationReports.CpuReports.1.ProcName UtilizationReports.CpuReports.1.MaxUsage
for that I use this this code:
db.Agents.aggregate(
[
{
"$project" : {
"UtilizationReports.Start" : 0.0,
"UtilizationReports.Interval" : 0.0,
"UtilizationReports.LastLogin" : 0.0,
"Configuration" : 0.0,
"HealthReports" : 0.0,
"_id" : 0.0
}
},
{
"$unwind" : {
"path" : "$UtilizationReports.CpuReports"
}
},
{
"$match" : {
"UtilizationReports.CpuReports.0" : {
"$exists" : true
},
"UtilizationReports.0.CpuReports.0.ProcName" : {
"$exists" : true
}
}
}
],
{
"allowDiskUse" : false
}
);
and I get this data
but I want to pivot row "ProcName" to column and the value will be "MaxUsage"
I try this code but it doesn't work:
db.Agents.aggregate(
[
{
"$project" : {
"tmp" : {
"$arrayToObject" : {
"$zip" : {
"inputs" : [
"$items.key",
"$items.value"
]
}
}
}
}
},
{
"$group" : {
"_id" : {
"Ip" : "$Ip",
"StartReport" : "$UtilizationReports.Start"
},
"items" : {
"$addToSet" : {
"key" : "$UtilizationReports.CpuReports.ProcName",
"value" : "$UtilizationReports.CpuReports.MaxUsage"
}
}
}
},
{
"$addFields" : {
"tmp.Ip" : "$_id.Ip",
"tmp.StartReport" : "$_id.StartReport"
}
},
{
"$replaceRoot" : {
"newRoot" : "$tmp"
}
}
],
{
"allowDiskUse" : true
}
);
the error message:
ad projection specification, cannot include fields or add computed fields during an exclusion projection: { UtilizationReports.Interval: 0.0, UtilizationReports.LastLogin: 0.0, Configuration: 0.0, HealthReports: 0.0, _id: 0.0, tmp: { $arrayToObject: { $zip: { inputs: [ \"$items.key\", \"$items.value\" ]
The sample output:

Answer 1

$arrayToObject is New in version 3.6.
I use with mongoDB version 3.4