Поскольку моя версия Oracle SQL не позволяла использовать Select * ниже, это код, который использовался для его работы.
Благодаря Dnoeth.
select
dt.enquiry_number,
dt.enquiry_time,
dt.service_code,
dt.enq_status_code,
dt.enquiry_desc,
dt.outstanding_flag,
-- latest status per enquiry_number
first_value(dt.enq_status_code)
over (partition by dt.enquiry_number
order by dt.enquiry_time desc) as last_status
from
(
select
central_enquiry.enquiry_number,
central_enquiry.enquiry_time,
central_enquiry.service_code,
enquiry_status_log.enq_status_code,
central_enquiry.enquiry_desc,
central_enquiry.outstanding_flag,
-- latest status per enquiry_number
first_value(enquiry_status_log.enq_status_code)
over (partition by enquiry_status_log.enquiry_number
order by central_enquiry.enquiry_time desc) as last_status
from
central_enquiry
inner join enquiry_status_log on central_enquiry.enquiry_number =
enquiry_status_log.enquiry_number
where
central_enquiry.service_code = 'GABV' and
((central_enquiry.enquiry_time > ADD_MONTHS(SYSDATE,-1) AND
central_enquiry.enquiry_time < SYSDATE))
) dt
where enq_status_code in ('EN13', 'EN93')
and last_status <> '1100'
order by enquiry_number