select 
a.CODE
,CUST_NAME  as  NAME
,CNT
,TTL_AMT
,ROUND(TTL_AMT/CNT,0)   as  AVG_AMT
from
(
    select 
    CUST_CODE   as  CODE
    ,SUM(ORDER_AMNT)*1.0    as  TTL_AMT
    from ORDERS
    where ORDER_DATE BETWEEN '2023-09-01'   AND '2023-09-30'
    GROUP BY 
    CUST_CODE
)a
INNER JOIN
(
    select 
    CUST_CODE   as  CODE
    ,COUNT(*)*1.0    as  CNT
    from ORDERS
    where ORDER_DATE BETWEEN '2023-09-01'   AND '2023-09-30'
    GROUP BY 
    CUST_CODE
    HAVING COUNT(*)>=5
)b
ON
a.CODE= b.CODE
LEFT OUTER JOIN
CUSTOMER    C
ON
a.CODE=C.CUST_CODE
ORDER BY 
CNT desc
,ROUND(TTL_AMT/CNT,0) desc
,a.CODE
LIMIT 5