Nested Array search in MongoDB/PyMongo while using aggregate

Question

I am trying to search for a keyword inside array of arrays in a Mongo document.

{
  "PRODUCT_NAME" : "Truffle Cake",

  "TAGS": [
            ["Cakes", 100],
            ["Flowers", 100],
       ]
}

Usually, I would do something like this and it would work.

db.collection.find( {"TAGS":{"$elemMatch":{ "$elemMatch": {"$in":['search_text']} } }} )

But now, I changed this query to an aggregate based query due to other requirements. I've tried $filter , $match but not able to replicate the above query exactly..

Can anyone convert the above code so that it can directly work with aggregate? (I use PyMongo)

Answer 1

$match uses the same query syntax as the query language (find), from the docs:

The query syntax is identical to the read operation query syntax;

This means if you have a query that works in a "find", it will also work within a $match stage, like so:

db.collection.aggregate([
  {
    $match: {
      "TAGS": {
        "$elemMatch": {
          "$elemMatch": {
            "$in": [
              "Cakes"
            ]
          }
        }
      }
    }
  }
])

Check this live on Mongo Playground