select
    CASE strftime('%w',SALES_DATE)
        WHEN '0' THEN '日'
        WHEN '1' THEN '月'
        WHEN '2' THEN '火'
        WHEN '3' THEN '水'
        WHEN '4' THEN '木'
        WHEN '5' THEN '金'
        WHEN '6' THEN '土'
        END AS WEEK
FROM SALES,
ORDER BY WEEK;