I have MongoDB documents structured like this:
{
"_id": "5d8b987f9f8b9f9c8c8b9f9",
"targetsList": [
{
"target": "user",
"statusList": [
{
"date": "2018-01-01",
"type": "OK"
},
{
"date": "2018-01-02",
"type": "FAILD"
}
]
}
]
}
And I want to count all documents that in their "targetList" array, there is an object with "target"=="user" - and also that object conatin on the last element of its "statusList" array, an object with "type" != "FAILD".
Any ideas on how to implement this kind of query?
Mongo playground: https://mongoplayground.net/p/3bCoHRnh-KQ In this example, I expected the count to be 1, because only the second object meets the conditions.
CodePudding user response:
An aggregation pipeline
1st step - Filtering out where "targetsList.target": "user"
2nd step - $unwind
on targetsList
to get it out of array
3rd step - getting the last element of the targetsList.statusList
array using $arrayElemAt
4th step - getting the results where that last element is not FAILD
5th step - getting the count
demo - you can try removing parts of the pipeline to see what the intermediate results are
db.collection.aggregate([
{
$match: {
"targetsList.target": "user"
}
},
{
$unwind: "$targetsList"
},
{
$project: {
"targetsList.statusList": {
$arrayElemAt: [
"$targetsList.statusList",
-1
]
},
}
},
{
$match: {
"targetsList.statusList.type": {
$ne: "FAILD"
}
}
},
{
$count: "withoutFailedInLastElemCount"
}
])
CodePudding user response:
Unless it's crucial that the element be the last index, this should work for your case.
db.collection.find({
"targetsList.statusList.type": {
$in: [
"FAILD"
]
}
})
This will retrieve documents where the type
value is FAILD
. To invert this you can swap $in
for $nin
.
Updated playground here