I have a MongoDB storing data from different sensors. It has the following structure:
{
"_id" : 1,
"sensorName" : "Heart Rate",
"samplePeriod" : 1000,
"data" : [
{
"timestamp" : NumberLong("1483537204046"),
"dataPoints" : [ 68 70 ]
},
{
"timestamp" : NumberLong("1483537206046"),
"dataPoints" : [ 68 70 ]
}
]
}
{
"_id" : 2,
"sensorName" : "Ambient Light",
"samplePeriod" : 500,
"data" : [
{
"timestamp" : NumberLong("1483537204058"),
"dataPoints" : [ 56, 54, 54, 54 ]
},
{
"timestamp" : NumberLong("1483537206058"),
"dataPoints" : [ 56, 54, 54, 54 ]
}
]
}
Now for example i need the "Heart Rate" - document with all of its fields and those of its "data" - subdocuments matching the condition "timestamp between 1483537204000 and 1483537214000".
I know about aggregation but cant figure out, how to not only return the matching subdocuments but to return the whole "Heart Rate" - document containing only the matching subdocuments in "data".
Is my structure efficient at all? Do you have any hint for a better structure for efficient querying for such data?
Thanks in advance!
You can try something like below.
$match to keep the heart rate record.
$filter to filter the subdocument with the condition.
$project to display the results.
aggregate([{
$match: {
"_id": 1
}
}, {
"$project": {
"_id": 1,
"sensorName": 1,
"samplePeriod": 1,
"data": {
"$filter": {
"input": "$data",
"as": "result",
"cond": {
$and: [{
$gte: ["$$result.timestamp", 1483537204000]
}, {
$lte: ["$$result.timestamp", 1483537214000]
}]
}
}
}
}
}])
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.