Mongodb update with upsert and multi syntax

Question

I am new to mongodb and so stressed out because of mongodb\'s incomplete documentation leaving me for trial and error... sadly, all my attempts are not working with no error

Answer 1

You cannot update multiple records based on different criteria and expect "upsert" to figure out what you mean. Upsert flag can cause insertion of at most one document and if you check the documentation you'll see that it doesn't make sense to have a "compound" criteria for update in case of an upsert.

In your example, which of the two fbid values should the insert use?

I think in your case you can take several approaches (all involve more than a single operation). You can update using the upsert flag in a loop calling update once for each fbid value - this will work like you expect and if fbid is not found a new document for it will be created. Other ways involve querying before running the update but I think those ways may be more prone to race conditions.

Here is explanation of how update works - I find it pretty complete: http://docs.mongodb.org/manual/core/update/#update-operations-with-the-upsert-flag