Change Values to Keys in MongoDB aggregation query - mongodb

Question

I have analytics documents in MongoDB that look like this:
{
"_id" : ObjectId("id1"),
"userObjectId" : "abc",
"eventType" : "First Signup",
"date" : ISODate("2017-09-10T20:46:42.144Z")
}
{
"_id" : ObjectId("id2"),
"userObjectId" : "abc",
"eventType" : "First Launch",
"date" : ISODate("2017-09-10T20:46:31.291Z")
}
Now I have constructed a query to group the results by date and event type:
{
"collection": "Analytics",
"aggregate": [
{
"$project": {
"yearMonthDay": {
"$dateToString": {
"format": "%Y-%m-%d",
"date": "$date"
}
},
"date": 1,
"userObjectId": 1,
"_id": 1,
"eventType": 1
}
},
{
"$group": {
"_id": { "ymd": "$yearMonthDay", "event": "$eventType" },
"num_in_group_count": {
"$sum": 1
},
"date": { "$last": "$yearMonthDay" },
"event": { "$last": "$eventType" }
}
}
]
}
This does generate data by date and type like so:
{
"_id" : {
"ymd" : "2017-09-10",
"event" : "First Signup"
},
"num_in_group_count" : 2.0,
"date" : "2017-09-10",
"event" : "First Signup"
}
{
"_id" : {
"ymd" : "2017-09-10",
"event" : "First End Onboarding"
},
"num_in_group_count" : 1.0,
"date" : "2017-09-10",
"event" : "First Launch"
}
However I would like to graph this in Redash, so would really like the data structured with the events changed to keys like so:
{
"_id" : "2017-09-10",
"First Signup" : 2.0,
"First Launch" : 1.0,
"date" : "2017-09-12"
}
How can I achieve this query?

Answer 1

you should group by date first
Then use this query to get result kindly check for null values for First Signup & Login
db.getCollection('heya').aggregate([
{
"$group": {
"_id": "$date",
"First Login": {
"$sum": {
"$cond": {
"if": {
"$eq": [
"$eventType",
"First Launch"
]
},
"then": 1,
"else": 0
}
}
},
"First Signup": {
"$sum": {
"$cond": {
"if": {
"$eq": [
"$eventType",
"First Signup"
]
},
"then": 1,
"else": 0
}
}
},
"date": {
"$addToSet": "$date"
}
}
},
{
"$unwind": "$date"
}
]);