How to search for documents based on the value of adding 2 properties on the document?

Question

I have a document:

{"price1": 500, "price2": 500}

I want to find all documents where "(price1 + price 2) < 1200". I assume I can do this by using the aggregation framework, but not seeing the correct way.

Answer 1

You can do it using $add. Try the following code:

db.collection.aggregate([
    { $project: { total: { $add: [ "$price1", "$price2" ] } } }, 
    { $match: {total: {$lt: 1200  }} }
])