SQL> select

  2  distinct qc_m|| ',' ||

  3  to_char(logon_dt, 'YYYY-MM-DD HH24:MI:SS')|| ',' ||

  4  CASE WHEN logon_dt IS NOT NULL THEN 'LOGON' ELSE 'LOGOFF' END

  5  from qc_ct2 qc left join v_tls_equipment_logon tls on qc.qc_m=tls.equipment_id where

  6  qc.terminal_c='T'and tls.USER_TYPE_C='1' and tls.site_c='C' order by 1 asc;

select qc_m from qc_ct2 where terminal_c='T';

select qc_m from qc_ct2 qc left join v_tls_equipment_logon tls on qc.qc_m=tls.equipment_id 
where 
case when (USER_TYPE_C='1' and (USER_TYPE_C!='1' and logon_dt IS NULL))
then USER_TYPE_C='1'
else (USER_TYPE_C='1' or (USER_TYPE_C!='1' and logon_dt IS NULL)
end
and terminal_c='T'
and site_c='C' order by 1 asc;