How to update ~20,000 records in MongoDB with this criteria

Question

I have a MongoDB document that looks like the following:

\"sport\": \"NFL\",
\"team_id\": 5,
\"week_num\": 6,
\"meta\": {
   .... more data ....,
   \"season         


        

Answer 1

The problem is that during the update, you can not refer the document you are updating. So you can not achieve what you want in one query.

You need to iterate through all the documents and save them one by one:

db.yourCollection.find({}).forEach(function(doc) {
  doc.season_year = doc.meta.season_year;
  db.yourCollection.save(doc);
});