How to query mongodb with a regex in the projection?

Question

Does anyone know if there is a way to query MongoDB and have only certain fields returned by using a regex as part of the projection?

For example: Given a collection having arbitrary field names, how might I query the collection and only return field names matching the regex '^foo'.

Possibly something like this?

db.mycollection.find({},{$regex:"^foo"})

Thanks. Brent.

That is not possible. There are some other projection possibilities: http://docs.mongodb.org/manual/reference/operator/projection/ — Haneev, Jan 06 '14 at 18:25
You may wish to switch to a key value store here if you are doing those queries — Sammaye, Jan 06 '14 at 22:50
Old version of MongoDB, newer versions allow the use of regex in projections. — Miguel Ortiz, Jun 18 '19 at 18:52

score 2 · Answer 1 · edited Jul 11 '20 at 21:49

2

I think you need to break down the process into two pieces, the first one is retrieving the fields names from MongoDB.

Then the second piece is that you can run the regex on the result, and from there you can query the DB with the right fields.

edited Jul 11 '20 at 21:49

Guy

answered Apr 12 '14 at 17:07

Baraa Al-Bourghli

1 Answers1