MongoDB: A complex query with array input - node.js

Question

I'm stuck at finding a solution for the following query.
1) a user can select many categories and subcategories.
2) the user can see all other users how are selected the same categories and subcategories within a certain radius.
Here is the Schema of the user
const userSchema = new Schema(
{
image: { type: String, default: 'NA' },
firstName: { type: String, default: 'first name' },
lastName: { type: String, default: 'last name' },
email: { type: String, lowercase: true, unique: true, trim: true },
password: { type: String, min: 6 },
gender: { type: String, emun: ['male','female','other'] },
about: { type: String, default: 'about you' },
address: {
zipCode: { type: Number, default: 000000 },
place: { type: String, default: 'place' },
street: { type: String, default: 'street' },
country: { type: String, default: 'Country' },
location: {
type: { type: String, default:'Point'},
coordinates: { type:[Number], index:'2dsphere', default:[0,0] }
}
},
interests: [
{
_id : false,
category: {
id: { type: Schema.Types.ObjectId, ref: 'Category' },
name: { type: String }
},
subCategory: [
{
_id : false,
id: { type: Schema.Types.ObjectId, ref: 'Subcategory' },
name: { type: String }
}
]
}
]
}
);
In my controller here is what I tried
homeData: async (req, res, next) => {
const limit = Number(req.params.limit);
const { latitude, longitude, minDistance, maxDistance } = getUserCurrentLocation(req);
const usersWithSameInterests = await User.aggregate([
{
"$geoNear": {
"near": {
"type": "Point",
"coordinates": [longitude, latitude]
},
"distanceField": "distance",
"minDistance": minDistance,
"maxDistance": maxDistance,
"spherical": true,
"query": { "location.type": "Point" }
}
},
{
"$match": { "interests": { "$elemMatch": {name: 'Sports'} }} // hard coded for testing
},
{ "$sort": { "distance": 1 } },
{ "$limit" : limit },
{
"$project": {
"_id": 1,
"image": 1,
"firstName":1,
"lastName":1,
"distance": 1,
"createdAt": 1
}
}
]);
return respondSuccess(res, null, {
newNotification: false,
usersWithSameInterests: usersWithSameInterests
});
},
The response i'm getting is
{
"success": true,
"message": "query was successfull",
"data": {
"newNotification": false,
"usersWithSameInterests": []
}
}
Sample categories and subcategories
Category: Sports
Subcategories: Cricket, Football, Hockey, Tennis
Category: Learning Languages
Subcategories: English, German, Spanish, Hindi
looking forward for much-needed help.
thank you.

Answer 1

It seems that you have a few mismatched columns.
On the $geonear pipeline, the line "query": { "location.type": "Point" } should be: 'query': {'address.location.type': 'Point'}.
And on the $match pipeline, the line { "interests": { "$elemMatch": {name: 'Sports'} } should be 'interests': { '$elemMatch:' {'category.name': 'Sports'} }
Edit:
To match multiple interests on the category and subcategory field, You can use the $in operator on the $match pipeline. Like this:
{
'interests.category.name': { $in: ['Sports'] },
'interests.subCategory.name': {$in: ['Soccer']}
}
It'll return anyone that have Sports in the category name, and Soccer on subcategory name.