Excluding Weekend dates from existing query

Question

I have the following query that returns the average of the total sum between start and end date of a status.
How do I take out the weekend dates so it doesn't include saturday and sunday.?
SELECT TRUNC(AVG( SUM ( (DECODE (status, 'Estimator Notified' ");
,cc.end_date,NULL) - DECODE (cc.status, 'Estimator Notified',cc.start_date,NULL)))),1)
FROM cc_request_status cc
group by cc.request_id

Answer 1

The above solution actually generates each date in a range and tests it for a Saturday or Sunday date. A more efficient solution calculates the weekend days directly by using the following facts:
1) For each whole week in the range the number of weekends days is 2.
2) For the partial week, a function can be made based on the ending day and the number of partial days to calculate the number of weekend days.
The following code uses the above two facts to calculate the number of days in a range excluding weekends:
SELECT NUM_DAYS - (WEEKS*2) -
       CASE WHEN REMAINDER = 0 THEN 0
            WHEN END_DOW = 7 THEN 1
            ELSE
                CASE
                    WHEN END_DOW > REMAINDER THEN 0
                    WHEN END_DOW = REMAINDER THEN 1
                    ELSE 2
                END
       END BUS_DAYS
FROM
    SELECT END_DOW, NUM_DAYS, FLOOR(NUM_DAYS/7) WEEKS, MOD(NUM_DAYS,7) REMAINDER
    FROM
        SELECT (TO_NUMBER(TO_CHAR(END_DATE, 'J')) -
                TO_NUMBER(TO_CHAR(START_DATE, 'J'))) + 1 NUM_DAYS,
               TO_NUMBER(TO_CHAR(END_DATE,  'D')) END_DOW
        FROM
          SELECT TO_DATE('05/05/2007','MM/DD/YYYY') START_DATE,
                 TO_DATE('05/14/2007','MM/DD/YYYY') END_DATE
          FROM DUAL
);You can collapse some of the inline views down, I expanded them to show each step.
JR