MongoDb: Combine two find operations together - mongodb

Question

When I search for documents containing title 'Apple' as such:
db.getCollection('items').find({title: {$regex: 'Apple'}})
The documents with title containing 'Apple' are returned as expected
When I search for documents where priceA is less than priceB as such:
db.getCollection('items').find({"$where":"this.priceA < this.priceB"})
The documents where priceA is less than priceB are returned as expected.
However, when I try to do both together as such:
db.getCollection('items').find({title: {$regex: 'Apple'}},
{"$where":"this.priceA < this.priceB"})
Only the _id field is returned, and it's really all the documents in my collection and the two filters above are not applied at all:
How do I apply both filters?

Answer 1

Your query is wrong try this. You are passing the second condition wrong in projection method check this out for more details
Mongodb find() method takes 3 arguments
condition:{title: {$regex: 'Apple'},"$where":"this.priceA < this.priceB"}
Projection:
By default t you wont specify any thing in projection it will return you the entire document but if you want only specific details you can pass it like {name:1,email:1}
Options:
sample example is{sort:1,limit:1}
db.getCollection('items').find({title: {$regex: 'Apple'},"$where":"this.priceA < this.priceB"}, {})