Inserendo queste parti nella posizione corretta del tuo $group._id può raggiungere il tuo obiettivo.
ampm : {
$cond : {
"if" : {
$lt : [ {
$hour : "$StartTime"
}, 12 ]
},
"then" : "AM",
"else" : "PM"
}
},
segment : {
$let : {
"vars" : {
h : {
$hour : "$StartTime"
}
},
"in" : {
$cond : {
"if" : {
$lt: [ "$$h", 6 ]
},
"then" : "Night",
"else" : {
$cond : {
"if" : {
$lt : [ "$$h", 12 ]
},
"then" : "Morning",
"else" : {
$cond : {
"if" : {
$lt : [ "$$h", 18 ]
},
"then" : "Afternoon",
"else" : "Evening"
}
}
}
}
}
}
}
}
Per rendere più facile la comprensione, incollo qui l'intero
[
{
"$match": {
"Category": {
"$in": ["Mobile"]
},
"StartTime": {
"$gte": {"$date": "2014-01-29T00:00:00.000Z"},
"$lt": {"$date": "2014-09-29T00:00:00.000Z"}
}
}
},
{
"$group": {
"_id": {
"Category": "$Category",
"Country":"$Country",
"City":"$City",
"day": {
"day":{"$dayOfMonth": "$StartTime"},
"month":{"$month":"$month"},
"year":{"$year":"$year"},
// add this part to group by for each day of each month of each year
ampm : {
$cond : {
"if" : {
$lt : [ {
$hour : "$StartTime"
}, 12 ]
},
"then" : "AM",
"else" : "PM"
}
},
segment : {
$let : {
"vars" : {
h : {
$hour : "$StartTime"
}
},
"in" : {
$cond : {
"if" : {
$lt: [ "$$h", 6 ]
},
"then" : "Night",
"else" : {
$cond : {
"if" : {
$lt : [ "$$h", 12 ]
},
"then" : "Morning",
"else" : {
$cond : {
"if" : {
$lt : [ "$$h", 18 ]
},
"then" : "Afternoon",
"else" : "Evening"
}
}
}
}
}
}
}
}
}
},
"UniqueVisits": {
"$sum": 1
},
"Date": {
"$first": "$StartTime"
}
}
},
{
"$project": {
"_id": "$_id.Category",
"Header": {
"$concat": [{"$substr": [{"$month": "$Date"}, 0,2]},
"/",
{"$substr": [{"$dayOfMonth": "$Date"}, 0, 2]},
"/",
{"$substr": [{"$year": "$Date"}, 0, 4]}]
},
"Name": {
"$concat": [
{
"$ifNull": ["$_id.Country","notset"]
},
"~",
{
"$ifNull": ["$_id.City","notset"]
}
]
},
"UniqueVisits": "$UniqueVisits",
}
}
]
