[{"collection":"olist_order_items_datasets","count":10,"content":{"_id":{"type":"objectId"},"product_id":{"type":"stringFromParts","parts":[{"type":"objectId"}]},"seller_id":{"type":"stringFromParts","parts":[{"type":"objectId"}]}}}]

db.olist_order_items_datasets.aggregate([{"$match":{"product_id":{"$type":"string"},"seller_id":{"$type":"string"}}},{"$set":{"product_id":{"$toObjectId":"$product_id"},"seller_id":{"$toObjectId":"$seller_id"}}},{"$merge":"olist_order_items_datasets"}])