Sqlite replace with lower

Hi
I want to replace scores in sqlite table:
this is working for me:
sqlQuery = String.Format (“replace into tableScores(nameUser, scores) values ("{0}","{1}")”, nick, scores);

But there is problem when user register as “Player” and then login as “player” and in database there is not “player” so I tried this:

sqlQuery = String.Format (“replace into tableScores(lower(nameUser), scores) values ("{0}","{1}")”, nick.ToLower(), scores);

but it not working

There’s nothing difficult here

    string playerName = "Player";
    Debug.Log(playerName.ToLower());
if(username.ToLower() == playerName.ToLower())
// Your code here