I am trying to match the fields of originalEmail with a mail address like liron@gmail.com, but no matter, case sensitive means to also find LirOn@gmail.com fiel
originalEmail
You can use Builders.Filter.Regex.
Builders.Filter.Regex
public async Task GetEntityIdByOriginalEmail(string originalEmail) { var collection = GetCollection(); var filter = Builders.Filter.Regex("x", new BsonRegularExpression(originalEmail, "i")); return await collection.Find(filter).FirstOrDefaultAsync(); }