Aggregate documents where objects in array matches multiple conditions - mongodb

Question

I have a collection with documents similar to such:
{
"_id": ObjectId("xxxxx"),
"item": [
{ "property": ["attr1", "+1"] },
{ "property": ["attr2", "-1"] }
]
}
{
"_id": ObjectId("xxxxy"),
"item": [
{ "property": ["attr1", "-1"] },
{ "property": ["attr2", "0"] }
]
}
{
"_id": ObjectId("xxxxz"),
"item": [
{ "property": ["attr1", "0"] },
{ "property": ["attr2", "+1"] }
]
}
Preferably using an aggregation pipeline, is there any way to match the document if and only if any one of the properties match more than one condition?
For example, I want a query where one object in the array matches both of these conditions:
("item.property": "attr1") AND ("item.property": /^\+/)
That is, a single property where it contains "attr1" and an element that starts with "+".
However, using my current query that looks like this:
collection.aggregate(
{ $match:
{ $and:
[
{ "item.property": "attr1" },
{ "item.property": /^\+/ }
]
}
}
This would match both the first and last document because both contain a property with "attr1" and an element that stats with "+". However, I do not want this query to match the last document, since the element that starts with "+" does not belong to the same object in the array.
Is there any way to achieve this behavior using the aggregation framework?

Answer 1

You can use the below query with $elemMatch to match the array's both values.
Something like
db.collection_name.aggregate({
"$match": {
"item": {
"$elemMatch": {
"property.0": "attr1",
"property.1": /^\+/
}
}
}
});
Also, you can use $all operator if you don't want to reference array index.
db.collection_name.aggregate({
"$match": {
"item": {
"$elemMatch": {
"property": {
"$all": [
"attr1",
/^\+/
]
}
}
}
}
});