$or doesn't work for subdocument level search - node.js

Question

Search retrieves result only in parent level. search with $or condition returns empty array for subdocument level filter/search. $or doesn't work for subdocument level search. Any fixes for this or any mistakes in my code?
exports.getAllProduct = (req, res, next) => {
categories.find({$or:[{“categoryName”:{ $regex: req.params.id, $options: ‘i’ }},
{“subcategory.$.productName”:{ $regex: req.params.id, $options: ‘i’ }}]},
(err, products) => {
console.log(“Products:“+JSON.stringify(products));
if (err) {
return res.status(400).json({
error: “No Products found”+err
});
}
res.status(200).json(products)
});
};
const categorySchema = new mongoose.Schema({
categoryName: {
type: String,
trim: true
},
subcategory: [ {
subcategoryName: {
type: String,
trim:true
},
productCode: {
type: String,
trim: true
}]});
http://localhost:3000/category/getAllProduct/fruits
What mistake why $or is not working? I'm using mongoDB 4.4.1 and mongoose 5.10.8 and Mac OS Catalina.

Answer 1

As I can see sub-category is an array..you should check in the second parameter of the $or if the input is “$in” array.
Check this post
MongoDB query IN array of object

Answer 2

If I'm reading your mongo query correctly, you have a $ in subcategory.$.subcategoryName which is most likely causing the issue you are seeing. Use subcategory.subcategoryName to query against that value.
See below:
categories.find({
$or:[
{
“categoryName”:{
$regex: req.params.id,
$options: 'i'
}
},
{
“subcategory.subcategoryName”: {
$regex: req.params.id,
$options: 'i'
}
}
]},
(err, products) => {}
);
Also, always try to format your code cleanly as in this example. It makes finding solutions easier.
If you do not need the query to be case insensitive the below query will be cleaner:
categories.find({
$or:[
{
“categoryName”: req.params.id
},
{
“subcategory.subcategoryName”: req.params.id
}
]},
(err, products) => {}
);