regex - How do I make case-insensitive queries on Mongodb?

Question

var thename = 'Andrew';
db.collection.find({'name':thename});

How do I query case insensitive? I want to find result even if "andrew";

Answer 1

Chris Fulstow's solution will work (+1), however, it may not be efficient, especially if your collection is very large. Non-rooted regular expressions (those not beginning with ^, which anchors the regular expression to the start of the string), and those using the i flag for case insensitivity will not use indexes, even if they exist.

An alternative option you might consider is to denormalize your data to store a lower-case version of the name field, for instance as name_lower. You can then query that efficiently (especially if it is indexed) for case-insensitive exact matches like:

db.collection.find({"name_lower": thename.toLowerCase()})

Or with a prefix match (a rooted regular expression) as:

db.collection.find( {"name_lower":
    { $regex: new RegExp("^" + thename.toLowerCase(), "i") } }
);

Both of these queries will use an index on name_lower.