I have a MongoDB database containing documents in the following format:
{
"name": "",
"surname": "",
"ssn": "",
"tests": [
{
"date": "",
"attending": [
{
"id": "",
"role": ""
}
]
}
]
}
A document contains, for each person, a list of tests with their relative information. I woud like to remove from each document only the subdocuments (belonging to the tests array) which were performed after a certain date (2019-02-22) and by a certain nurse (id = 0187).
Since all the dates are saved in string format, for date comparison I used the $dateFromString operator in the following way:
db.Vaccinations.aggregate([
"$match": {
"$expr": {
"$and": [
{
"$gte": [
{ "$dateFromString": { "dateString": "$tests.date"}},
ISODate("2019-02-22T00:00:00Z")
]},
{
"tests.attending.id" : "0187"
}
]
}
}
])
However I wasn't able to use the $pull operator to remove the coerresponding subdocuments. Is it possible to do so or is $pull the wrong operator?
Query
date < "2019-02-22"nurse != "0187"nurse != "0187" is checked using a path "$test.attending.id" to get all the ids of that test(an array), and test that the intersection with ["0187"] is empty => that nurse didn't do the test.*you can use updateOne or updateMany depending on your needs
*i didn't use $dateFromString if dates have the same format like
YYYY-MM-DD comparison will work, but in general save dates in the database, it makes things easier and faster.
update(
{},
[{"$set":
{"tests":
{"$filter":
{"input": "$tests",
"cond":
{"$or":
[{"$lt": ["$$test.date", "2019-02-22"]},
{"$eq":
[{"$setIntersection": [["0187"], "$$test.attending.id"]}, []]}]},
"as": "test"}}}}])