c# mongodb case sensitive search

Question

I have a collection in which I store Email and password of user.

I obviously don't want to require the user to insert his email case sensitive and to be exactly as when he first registered.

I'm using mongodb 2.0 c# driver, I'm repeating it because I saw solutions to queries written with regex but I'm afraid I cant user it in here.

my query looks like

var filter = Builders<ME_User>.Filter.And(
                                 Builders<ME_User>.Filter.Eq(u => u.Email, email),
                                 Builders<ME_User>.Filter.Eq(u => u.Password, password));
            ME_User foundUser = null;
            var options = new FindOptions<ME_User>
            {
                Limit = 1
            };
            using (var cursor = await manager.User.FindAsync(filter, options))
            {
                while (await cursor.MoveNextAsync())
                {
                    var batch = cursor.Current;
                    foreach (ME_User user in batch)
                        foundUser = user;
                }
            }

I have an issue with disorder, kill me, but I cant allow myself save this data again with lower case and have 2 copies of the same thing. Also, I want the email to be saved EXACTLY like the user inserted it.

Stefano Castriotta · Accepted Answer · 2015-10-10 20:18:28Z

6

Filtering on string fields in Mongodb is case sensitive without using regular expressions. Why exactly you cannot use regular expressions?

Your query can be edited like this:

var filter = Builders<ME_User>.Filter.And(
Builders<ME_User>.Filter.Regex(u => u.Email, new BsonRegularExpression("/^" + email + "$/i"), 
Builders<ME_User>.Filter.Eq(u => u.Password, password));

Notice the "^" and "$" signs to specify a complete word search and most important the case-insensitive operator at the end of the regular expression ("/i").

Another way vould be the Text search, that requires the creation of a text index and is case insensitive for latin alphabet: http://docs.mongodb.org/manual/reference/operator/query/text/#match-operation

In C#, you will use with the Text Filter:

var filter = Builders<ME_User>.Filter.And(
Builders<ME_User>.Filter.Text(email), 
Builders<ME_User>.Filter.Eq(u => u.Password, password));

With a text index query in an OR clause, you will need to create an index on Password field as well, otherwise the OR query will produce an error:

Other non-TEXT clauses under OR have to be indexed as well

answered Oct 10, 2015 at 20:18

Stefano Castriotta

2,9333 gold badges19 silver badges26 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Ori Refael Over a year ago

yeah, i meant no regex cause i saw people writing entire string object and not using the actual 2.0 driver. thats perfect!

andrewCanProgram Over a year ago

Worked great! Regex saves the day once again.

SJFJ · Accepted Answer · 2016-11-30 10:39:39Z

3

I'd prefer using Linq.

var match = theCollection.AsQueryable().SingleOrDefault(x =>
    x.Email.ToLower() == emailToSearchFor.ToLower());

answered Nov 30, 2016 at 10:39

SJFJ

6876 silver badges19 bronze badges

4 Comments

Piotr Kula Over a year ago

Yea that seems to work. I suppose you deserve an upvote.. but is it the most efficient way to do it? What if I have 200+ million documents?

SJFJ Over a year ago

@ppumkin I don't know if it is the most effective way you'd have to benchmark that. On the other hand, to me, it is far more readable. Are you planning to have 200+ million users? Can I buy some stocks? :)

Piotr Kula Over a year ago

Ummmm - Hahha I wish. No I am indexing documents from this game, PathOfExile and I have a subset of data now, 50million documents. I have tried Elastic, RavenDB, MongoDB to see which one is fastest. MongoDB is the worst for me.. 50seconds for the same query Elastic only 0.2second -- Umm, Yea?! But Elastic queries are super weird and also sometimes suffers 50second response times (but only sometimes). Maybe I am doing this wrong? :D I have no idea

PeterFromCologne Over a year ago

I lost so much time because I used .Equals() which is not supported but == is. Thanks for your answer

Karunakaran · Accepted Answer · 2021-10-29 07:20:04Z

0

For the c# driver 2.1 (MongoDB 3.0) By default its case-sensitive. To case-insensitive just add of "i" in BsonRegularExpression. please refer below

  var filter = Builders<Users>.Filter.Regex(k=>k.Name, new BsonRegularExpression(name, "i"));

  var users = await _mongoDbContext.Users.Find(filter).ToListAsync();

answered Oct 29, 2021 at 7:20

Karunakaran

4557 silver badges18 bronze badges

Collectives™ on Stack Overflow

c# mongodb case sensitive search

3 Answers 3

2 Comments

4 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

4 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related