MongoDB - Match all document not containing a combination of value - arrays

Question

Let's say I have three document structured like so :
{
"_id": 1,
"conditions": [
["Apple", "Orange"],
["Lemon"],
["Strawberry"]
]
},
{
"_id": 2,
"conditions": [
["Apple"],
["Strawberry"]
]
},
{
"_id": 3,
"conditions": [
["Apple", "Lime"]
]
}
And I have an array, I'll call it ARC for this example :
ARC = [
"Apple",
"Lime",
"Banana",
"Avocado",
"Cherry"
]
I would like to return all document in which all conditions subarray values can't be found in the ARC array.
For example, with the data above, the first document should be returned because :
The Apple AND Orange combination is not in the ARC array
Lemon is not in the ARC array
Strawberry is not in the ARC array
The second document shouldn't be returned because :
Apple is in the ARC array
And the third document shouldn't be returned because :
The Apple AND Lime combination is in the ARC array
I've tried
db.example.find({"conditions": {$not: {$elemMatch: {$all: [ARC]}}}})
But it seems way too simple.. So, as expected, it doesn't work.
I know mongoDB is pretty powerful with all the aggregation and stuff but I'm a bit lost.
Do you know if it's possible with a query alone and if so, what should I look for ?

Answer 1

The query below should solve your problem.
var ARC = [
"Apple",
"Lime",
"Banana",
"Avocado",
"Cherry"
];
db.test.find(
{ $expr: {
$eq: [
{ $filter: { input: "$conditions", as: "c", cond: { $setIsSubset: [ "$$c", ARC] } } },
[ ]
]
}
}
)
It's made up of lots of parts so I'll try to break it down a bit, The first part is $expr within a find (or can be used within a $match in an aggregation) this allows us aggregation expressions within the query. So this allows us to use a $filter.
The $filter expression allows us to filter down the arrays in the condition field to check if any are a subset of the array ARC passed in.
We can actually take that filter an execute it on its own using an aggregation query:
db.test.aggregate([
{ $project: {
"example" : { $filter: { input: "$conditions", as: "c", cond: { $setIsSubset: [ "$$c", ARC] } } }
} }])
{ "_id" : 1, "example" : [ ] }
{ "_id" : 2, "example" : [ [ "Apple" ] ] }
{ "_id" : 3, "example" : [ [ "Apple", "Lime" ] ] }
The last part of the query is the $eq which is taking the value that is created with the filter and then matching it against an empty array [ ].

Answer 2

This is an aggregation approach. You should use $setIsSubset.
Below should be helpful:
db.collection.aggregate([
{
$match: {
$expr: {
$eq: [
true,
{
$allElementsTrue: {
$map: {
input: "$conditions",
as: "c",
in: {
$not: {
$setIsSubset: [
"$$c",
[
"Apple",
"Lime",
"Banana",
"Avocado",
"Cherry"
]
]
}
}
}
}
}
]
}
}
}
])
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