I want to add a record to the collection if the key doesn't already exist. I understand MongoDB offers the upsert
for this so I did a
db.collection.update({"_id":"key1"},{"_id":"key1"},True)
This seems to work.
However in the Pymongo documentation it says that update is deprecated and use to update_one()
.
But:
db.collection.update_one({"_id":"key1"},{"_id":"key1"},True)
Gives:
raise ValueError('update only works with $ operators')
ValueError: update only works with $ operators
I don't really understand why update_one
is different and why I need to use a $
operator. Can anyone help?
This is because you didn't specify any update operator.
For example to $set
the id
value use:
db.collection.update_one({"_id":"key1"}, {"$set": {"id":"key1"}}, upsert=True)
Note that in the Mongo shell, this will simply replace the document with the new document.