ORDER BY alphanumeric characters only in SQLite

Question

I am sorting songs in SQLite (on Android). I want to order them:

1. Case-insensitive
2. With leading-digits at the end, by integer value.
3. Without punct

Answer 1

In my opinion, the highest performance approach is to create a trigger to fill a new field named sort_key. You will need a primary key.

CREATE TABLE songs (n INTEGER, name TEXT, 
                    sort_key TEXT, 
                    ID INTEGER PRIMARY KEY AUTOINCREMENT);

CREATE TRIGGER songs_key_trigger
    AFTER INSERT ON songs FOR EACH ROW
    BEGIN n
        Declare @sort_key as varchar(255)
        -- calculate and call here your slugify function
        -- to fill sort_key from 'new.n' and 'new.name'
        UPDATE songs 
          SET sort_key = @sort_key
          WHERE ID = new.ID;
    END

Realize that this approach is index friendly, you can create an index over new column to avoid table full scan operations.