The following lines contain the word 'select', 'insert', 'update' or 'delete':
select CREDIT_HISTORY_ID, LAST_UPDATE_DATE,
LAST_UPDATED_BY, LAST_UPDATE_LOGIN,
CREATION_DATE, CREATED_BY, CUSTOMER_ID,
ON_HOLD, HOLD_DATE, CREDIT_LIMIT, CREDIT_RATING,
RISK_CODE, OUTSTANDING_BALANCE, SITE_USE_ID
FROM AR_CREDIT_HISTORIES
WHERE CUSTOMER_ID = nvl(cust_id, CUSTOMER_ID)
AND creation_date between nvl(st_date, creation_date)
AND nvl(en_date, creation_date);