Updating single object in array in mongoDB - mongodb

Question

My collection is in below format,
{
"_id" : ObjectId("5d01fddd3f21c407582e578d"),
"device_name" : "Test Alarm Device",
"description" : "test",
"parameters" : [
{
"parameter_name" : "CO2",
"status" : "on"
},
{
"parameter_name" : "NO",
"status" : "on"
},
{
"parameter_name" : "O2",
"status" : "on"
}
}
Now I wish to overwrite(update) complete object where "parameter_name" : "O2".
For example, in new collection it will look like...
{
"parameter_name" : "O2",
"status" : "on",
"is_active": true,
"min": 5
}

Answer 1

Use $out to replace existing collection, $addFields to overwrite existing array and $map with $cond to update elements based on some criteria. To build a new object based on existing one you can use $mergeObjects, try:
db.collection.aggregate([
{
$addFields: {
parameters: {
$map: {
input: "$parameters",
in: {
$cond: [
{ "$eq": [ "$$this.parameter_name", "O2" ] },
{ $mergeObjects: [ "$$this", { "is_active": true, "min": 5 } ] },
"$$this"
]
}
}
}
}
},
{ $out: "collection" }
])

Answer 2

This will do, but I don't think it is the best solution:
db.collection.updateOne({
_id: ObjectId("5d01fddd3f21c407582e578d"),
{ $set: { "parameters" : [
{
"parameter_name" : "CO2",
"status" : "on"
},
{
"parameter_name" : "NO",
"status" : "on"
},
{
"parameter_name" : "O2",
"status" : "on",
"is_active": true,
"min": 5
}
]
}
}
)