Query in Embedded document - mongodb

Question

I want to do a query where i can reach all banks where bank is banco1 and investments are not equal to "box".
How can i do that? I tried this query, but don't work :
db.banks.find( { "investments": { $elemMatch: { bank: "banco1", productName: {$ne:"box} } } } );
This query it's one example of many that i have tried.
Thanks.
{
"_id": "5d3fc8c3914297c7b9a3a9e5",
"banco": "banco 1",
"investimentos": [{
"bank": "banco1",
"risk": "Conservador",
"expiryDate": "2021-10-04",
"tax": "1.02",
"discriminator": "investment",
"productName": "LCI"
},
{
"bank": "banco1",
"risk": "Conservador",
"expiryDate": "2020-06-24",
"tax": "0.75",
"discriminator": "investment",
"productName": "Fundo DI"
},
{
"bank": "banco1",
"risk": "Conservador",
"tax": "0.04",
"discriminator": "investment",
"id": "259ad8ac-57b7-4d33-8e75-46cf5c5c28e3",
"aniversary": "30",
"productName": "box"
}
}],
{
"_id": "5d3fcb4c914297c7b9a3a9e6",
"banco": "banco2",
"investimentos": [{
"bank": "banco2",
"risk": "Conservador",
"expiryDate": "2020-06-24",
"tax": "0.80",
"discriminator": "investment",
"id": "73db503f-c780-448c-a6a8-05d2837ff6ff",
"redemptionDate": "D+1",
"productName": "Fundo DI"
}
,
{
"bank": "banco2",
"risk": "Conservador",
"expiryDate": "2020-12-17",
"tax": "0.98",
"discriminator": "investment",
"id": "54e01515-dc7f-470f-8f00-8603c8f00686",
"productName": "LCA"
},
{
"bank": "banco2",
"risk": "Conservador",
"expiryDate": "2021-08-05",
"tax": "1.0",
"discriminator": "investment",
"id": "259ad8ac-57b7-4d33-8e75-46cf5c5c28e2",
"productName": "CDB"
}
}]

Answer 1

Welcome to SO Luan!
I've found that Mongo Aggregations give me all of the power available in find, and so much more functionality. So about 95% of the time, unless I'm doing a quick query, I end up going to aggregates.
The following aggregate will get you what you're looking for:
db.getCollection('Test').aggregate([
{ $unwind: "$investimentos"},
{ $match: {
'investimentos.bank': "banco1",
'investimentos.productName': /^(?!box$)/
}},
])
The $unwind pipeline takes the array of embedded documents in investimentos, and creates a new document, retaining the parent fields (_id and banco), for each element withing investimentos. You can try just db.getCollection('Test').aggregate([{ $unwind: "$investimentos"}]) to visually see what happens.
The $match pipeline does the same thing as the find method - you give it a list of filters to apply. The second element uses a regex (surrounded by '/' chars) to specify that it should find everything that does not start with "box".