I'm working on retrieving selective data from an array based on certain conditions. But I don't to unwind it. Is there any way in mongoDB to project a single element in array of objects which matches a condition.
1 Answers
The positional operator $ would be perfect here, from the docs:
The positional $ operator limits the contents of an to return the first element that matches the query condition on the array.
For input in the structure:
[
{
"arr": [
{
value: "other value"
},
{
value: "match this"
},
{
value: "dont match"
}
]
}
]
You just use this query:
db.collection.find({
"arr.value": "match this"
},
{
"arr.$": 1
})
Output:
[
{
"_id": ObjectId("5a934e000102030405000000"),
"arr": [
{
"value": "match this"
}
]
}
]
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