How to put where condition and join in cursor Android

Hi i want to put a where condition and join tables in my query but i can't find any example

as for now i'm using this code, but i don't know where to put the join and where condition

 public Cursor getUsers() {
    Cursor localCursor =
            this.myDataBase.query(TBL_INFO, new String[] {
                            KEY_ID,
                            KEY_NAME},
                    null,
                    null, null, null, null);

    if (localCursor != null)
        localCursor.moveToFirst();
    return localCursor;
}

I'm wondering what's with the null value? is there any syntax that i can follow? thank you for the help!