WITH RECURSIVE
    DATE_TBL(x) AS (
        SELECT
            '2022-08-01'
        UNION ALL
        SELECT
            DATE(x, '+1 days')
        FROM
            DATE_TBL
        LIMIT
            31
    )
SELECT
    x AS REGIST_DATE,
    SUBSTR('日月火水木金土', STRFTIME('%w', x) + 1, 1) AS WK,
    COUNT(USER_CODE) AS TOTAL
FROM
    DATE_TBL
LEFT OUTER JOIN
    USERS
ON
    VALID_FLG = 1
    AND DATE_TBL.x = STRFTIME('%Y-%m-%d', USERS.CONFIRMED_AT)
GROUP BY
    REGIST_DATE
ORDER BY
    REGIST_DATE
;