在计算值中计算平均值/最小值/最大值/总计

Question

EDIT: ADDED PL/SQL script:

I am running a script that calculates the time difference between two columns which are on different tables. It basically calculates the time a certificate took to be generated by the CA. I want to run average/min/max and the total of certificates generated in the last 10 minutes.

I managed to calculate the time delta but I do not get how can I gather the min/max/average on the calculated values. (I think I have to run the average on the elapsed value) but I do not manage. Do I have to declare elapsed to be able to perform calculations on it?

set serveroutput on
whenever sqlerror exit sql.sqlcode;
set echo off
SET VERIFY OFF
set heading off
SET FEEDBACK OFF
set serveroutput on size unlimited
set linesize 300
ALTER session SET TIME_ZONE='GMT';
Declare
vv_SchemaName VARCHAR2(15);
BEGIN
vv_SchemaName := Sys_Context('USERENV','CURRENT_SCHEMA');
FOR REVOKED IN (
select  a.transaction_id as trans_Id,
        e.eventcode,
        e.eventtime,
        a.time_received,
        round((e.eventtime - a.time_received) * 86400) as elapsed
  from      request_history_tbl a 
        join
            eventlog_tbl e
          on a.transaction_id = e.transaction_id
  where e.eventtime >= current_timestamp - 2
    and e.eventcode = '50'
    )
    LOOP
    dbms_output.put_line('average_request_time' || ...)
    dbms_output.put_line('Min_request_time' || ...)
    dbms_output.put_line('max_request_time' || ...)
   
    END LOOP;
END;

how can i get the AVG/MIN/MAX in the dbms_output.put_lines?

Answer 1

If I understood you correctly, then query you wrote might be used as a CTE (or an inline view), ie a source you'll use to get what you want:

with temp as
  (select a.transaction_id,
          e.eventcode,
          e.eventtime,
          a.time_received,
          (e.eventtime - a.time_received) * 86400  as diff_in_seconds       
   from request_history_tbl a join eventlog_tbl e
     on a.transaction_id = e.transaction_id
   where e.eventtime >= current_timestamp - 10/1440
     and e.eventcode = '50'
  )
select avg(diff_in_seconds) avg_diff,
       min(diff_in_seconds) min_diff,
       max(diff_in_seconds) max_diff
from temp;

---

Switching to PL/SQL is easy; use that query in cursor FOR loop and display the result:

begin
  for cur_r in 
    (select avg(diff_in_seconds) avg_diff,
            min(diff_in_seconds) min_diff,
            max(diff_in_seconds) max_diff
     from (select a.transaction_id,
             e.eventcode,
             e.eventtime,
             a.time_received,
             (e.eventtime - a.time_received) * 86400  as diff_in_seconds       
           from request_history_tbl a join eventlog_tbl e
             on a.transaction_id = e.transaction_id
           where e.eventtime >= current_timestamp - 10/1440
             and e.eventcode = '50'
          )
    ) loop
      dbms_output.put_line(cur_r.avg_diff ||', '||
                           cur_r.min_diff ||', '||
                           cur_r.max_diff);
  end loop;
end;