Question

I have some values in a collection in a document. For example, my key range can be:

• 10 - 29
• 30 - 39
• 40 - 49

Those are all strings. I want to somehow search (in MongoDB) for strings starting with 10 and ending with 49. How can I do this?

I know I should have these as numbers, but that’s not possible due to the structure of how the system was created.

Thanks

Answer 1

You’re right, best option would have been to model these as numerals. However, my best (only) alternate suggestion would be to use a regex search.
See here for the docs on regex search for mongo and here for creating range expressions.

Depending on possible range, your query would be something like

db.collection.find( { range : /[1-4][0-9] - [1-4][0-9]/ } );

which matches your range options specified [10 - 29, 30 - 39, 40 - 49]. Note this would also match 49 - 10 for example, so you would need to harden that expression up if there are any exclusions not mentioned in the question.

Note regex queries come at a performance cost, remodeling and using built in $gt $lt functions would certainly be desirable.

Good luck!