Example of Oracle sorting by conditions

Requirement: the number of appointment cases on the current day is at the beginning --> the number of cases that have never been handled --> the last handling time is sorted from small to large (that is, the closer the collection is, the more the case is later)

That is: (col_case.case_app_date = sysdate) --> (col_case.case_lst_col_date is null) --> (col_case.case_lst_col_date)

Select case when trunc (T. case_app_date) = trunc (sysdate) Then '1'
When T. case_lst_col_date_str is null then '2'
Else '3' end as column1, T .*
From
(
Select v_coloverview_full. * From v_coloverview_full where mcol_id = 'hangq'
Or (agent_id = 'zhangq' and agent_status = 'agentstatus _ agree'
And agent_date_from <= sysdate and agent_date_to> = sysdate)
)
T
Order by column1, case_lst_col_date_str ASC