SELECT
    OD.CUST_CODE AS CODE
    , CS.CUST_NAME AS NAME
    -- DISTNCTで同一日付を1件とカウントする
    , COUNT(DISTINCT OD.ORDER_DATE) AS CNT 
FROM
    ORDERS AS OD 
    -- 顧客名を取得するため顧客テーブルを内部結合
    INNER JOIN CUSTOMER AS CS 
        ON CS.CUST_CODE = OD.CUST_CODE 
WHERE
    OD.ORDER_DATE BETWEEN '2023-07-01' AND '2023-07-31' 
GROUP BY
    OD.CUST_CODE 
    , CS.CUST_NAME
ORDER BY
    CNT DESC
    , CODE DESC;