Android SQLite fetch user_id

How can you fetch the user_id from the sqlite database?

I have a user table created like this (just a simple one):

private static final String CREATE_TABLE_USER =
    "CREATE TABLE " + TABLE_USER +
                "("+
                COLUMN_USER_ID + " integer primary key autoincrement," +
                COLUMN_USER + " TEXT NOT NULL, " +
                COLUMN_PASSWORD + " TEXT NOT NULL" +
                ");";

I want to get the user's information throughout the whole application (using shared preferences).

At my log in page, I only have 2 textFields: username and password. I can save these values as a variable, and put them in my createSession(String name, String email, Long userId) method. However, since I dont have an user_id textfield, I can't fetch the user_id .. that is needed for the createSession() method.

public void createSession(String name, String email, Long userId){

        // Storing name in pref
        editor.putString(KEY_NAME, name);

        // Storing password in pref
        editor.putString(KEY_PASSWORD, email);

        //Storing user id in pref
        editor.putLong(KEY_ID, userId);

        // commit changes
        editor.commit();
    }

I tried making a query to receive the ID, and return it to the log in page (where it will be put in the createSession() method)

public Long getUserId(String username, String password) throws SQLException
{
    Cursor mCursor = database.rawQuery("SELECT user_id FROM user WHERE username=? AND password=?", new String[]{username,password});
    if (mCursor != null) {
        if(mCursor.getCount() > 0)
        {
           Long userId = mCursor.getLong(1);
        }
    }
    return null;
}

But it won't fetch the userId for me .. anyone have a suggestion why this would be?