I am trying an aggregation in MongoDB in order to convert:
[
{
"_id": ObjectId("5a934e000102030405000000"),
"acronym": "MC",
"tickers": [
{
"name": "Sensor1-front",
"symbol": "s1f"
},
{
"name": "Sensor1-back",
"symbol": "s1b"
}
]
}
]
into something like this:
['s1f.MC','s1b.MC']
Where each symbol in tickers is concat to acronym.
I am trying it with $concat, $group, etc but I am not going anywhere.
Thanks!
You can use reduce
db.collection.aggregate([
{
$addFields: {
newField: {
"$reduce": {
"input": "$tickers",
"initialValue": [],
"in": {
"$concatArrays": [
[
{
"$concat": [
"$$this.symbol",
".",
"$acronym"
]
}
],
"$$value"
]
}
}
}
}
}
])
Working Mongo playground