SQL Report - query multiple tables - sql

Question

I have been working on a Stats page in APEX and currently have the following report query:
select to_char(DATELOGGED,'Month - YYYY') as Month,
COUNT(*) as "Total Calls",
SUM(case when CLOSED is null then 1 else null end) as "Open",
COUNT(case CLOSED when 'Y' then 1 else null end) as "Closed",
SUM(case when EXTREF is null then 0 else 1 end) as "Referred",
round((COUNT(case SLA_MET when 'Y' then 1 else null end)/COUNT(case CLOSED when 'Y' then 1 else null end)*100),2) as "SLA Met %"
from IT_SUPPORT_CALLS
GROUP BY to_char(DATELOGGED,'Month - YYYY')
order by MIN (DATELOGGED) desc
I wish to add the sum of DURATION from a different table:
select
"START_TIME",
DECODE(DURATION,null,'Open',((select extract( minute from DURATION )
+ extract( hour from DURATION ) * 60
+ extract( day from DURATION ) * 60 * 24
from dual)||' minutes')) DURATION
from "IT_DOWNTIME"
The IT_DOWNTIME table uses START_TIME (varchar2) as the date identifier, the IT_SUPPORT_CALLS uses DATELOGGED (DATE) as date identifier.
The current output for IT_DOWNTIME is for example:
08-FEB-2019 - 30 Minutes
20-FEB-2019 - 15 Minutes
I would like the report SUM and group IT_DOWNTIME and add this into the existing report.
Hope this makes sense.
Please let me know if I missed any information that would help to resolve this.
Many thanks
Thanks for that, much appreciated. Unfortunately it doesn't return any data from IT_DOWNTIME.
I'm guessing the different date formats doesn't help, hope this clears things up a bit:
These are the columns in IT_DOWNTIME that are of interest:
START_TIME ( VARCHAR2(30) )
DURATION ( INTERVAL DAY(2) TO SECOND(6) )
Example of current IT_DOWNTIME output without formatting:
START_TIME
06-JUL-2016 11:05
DURATION
+00 00:35:00.000000
Example of current IT_SUPPORT_CALLS output without formatting:
DATELOGGED
06/07/2016

Answer 1

Something like this will probably do it, but there has been some guesswork as to your column names etc:
SELECT *
FROM
(
SELECT
to_char(DATELOGGED,'MON-YYYY') as Month,
COUNT(*) as Total_Calls,
SUM(case when CLOSED is null then 1 else null end) as case_Open,
COUNT(case CLOSED when 'Y' then 1 else null end) as case_Closed,
SUM(case when EXTREF is null then 0 else 1 end) as case_Referred,
round((COUNT(case SLA_MET when 'Y' then 1 else null end)/COUNT(case CLOSED when 'Y' then 1 else null end)*100),2) as percent_SLA_met
FROM IT_SUPPORT_CALLS
GROUP BY to_char(DATELOGGED,'MON-YYYY')
) calls
LEFT JOIN
(
SELECT
SUBSTR(START_TIME, 4) as down_month,
SUM(extract(minute from DURATION) +
extract(hour from DURATION) * 60 +
extract(day from DURATION) * 60 * 24
) || 'minutes' as total_down_mins
FROM IT_DOWNTIME
WHERE duration is not null
GROUP BY SUBSTR(START_TIME, 4)
) downs
ON calls.month = downs.down_month
Changed your date formatting of the first query to be MON-YYYY to make it align with what you claim is the formatting of the varchar2 date of the second query (dd-mon-yyy), and substringed the date to remove the day, leaving just the month
Edit:
Ok, so since you've posted some different example data from IT_DOWNTIME I see the problem: there's a time on the date also. Your first sample data didn't contain this time, it was just a date (as a string) so I was doing...
SUBSTR('01-JAN-1970', 4)
...to reduce the day date to a month date ('JAN-1970') and this was intended to align with the stuff going on in the other table ( to_date() with a format of 'non-yyyy' )
Now we know that there is a time in there too, of course it won't align because...
SUBSTR('01-JAN-1970 12:34', 4)
...produces 'JAN-1970 12:34' and this will then not match to anything from the other table (which will be just 'JAN-1970' without the time), so the left join means that nulls will be output
The solution is to change the SUBSTR call so it cuts 8 characters, starting at position 4:
SUBSTR(start_time, 4, 8)
This will remove the day and the time, leaving just the month-year that we need. You'll need to make the change in two places in the query above..

Answer 2

Apologies for the delay on replying to this. However, that is working perfectly Caius, thanks very much! So to be complete, had to change your above code to:
SUBSTR(START_TIME, 4, 8) as down_month,
and
GROUP BY SUBSTR(START_TIME, 4, 8)