How do I sort by month ? using the "Month" format

Question

Hello All,
Is it possible to sort by month using the follwoing SQL.
Select TO_CHAR (RCA_CLOSE_DATE, 'MON-YY') "Month",
SUM (ADJUSTMENT_INCL_GST)
From My_Table
Group By TO_CHAR (RCA_CLOSE_DATE, 'MON-YY')
Output
Month Sum(Adjustment Incl Gst)
APR-06 $6,539,983.08
AUG-06 $23,122,705.31
FEB-06 $14,365,106.52
JUL-06 $19,776,122.04
JUN-06 $20,161,278.12
MAR-06 $8,248,955.87
MAY-06 $18,498,683.04
NOV-06 $24,120,095.49
OCT-06 $12,781,721.23
SEP-06 $15,632,604.21
Hope someone can help
Frank

Answer 1

If the desired sort order is MM-YYYY, then how would...
ORDER BY
    TO_CHAR(RCA_CLOSE_DATE, 'MM-YYYY') ...not achieve this?
Perhaps the original poster could clarify what they mean by "sort by month". In numeric order by month then year, in numeric order by year then month, or in some other order?
If you do not like TO_CHAR, another approach (again assuming "numeric order by month then year" is what is desired) might be:
SELECT
    TO_CHAR(RCA_CLOSE_DATE, 'MON-YY') AS MONTH,
    SUM(ADJUSTMENT_INCL_GST) AS TOTAL
FROM
    MY_TABLE
GROUP BY
    EXTRACT(MONTH FROM RCA_CLOSE_DATE),
    EXTRACT(YEAR FROM RCA_CLOSE_DATE),
    TO_CHAR(RCA_CLOSE_DATE, 'MON-YY')
ORDER BY
    EXTRACT(MONTH FROM RCA_CLOSE_DATE),
    EXTRACT(YEAR FROM RCA_CLOSE_DATE)In any event, in a query with GROUP BY clause:
1. The expression(s) in ORDER BY clause do not need to appear in the SELECT clause.
2. The expression(s) in ORDER BY clause do need to appear in the GROUP BY clause (unless you want to order on the result of an aggregate expression, like involving SUM, which does not appear to be the case here).
3. Expressions in the SELECT clause do need to appear in the GROUP BY clause, unless they are aggregate expressions, like involving SUM.
Hope this helps.
P.S. If the desired order is "in numeric order by year then month", then you might use TRUNC like this:
SELECT
    TO_CHAR(RCA_CLOSE_DATE, 'MON-YY') AS MONTH,
    SUM(ADJUSTMENT_INCL_GST) AS TOTAL
FROM
    MY_TABLE
GROUP BY
    TRUNC(RCA_CLOSE_DATE, 'MONTH'),
    TO_CHAR(RCA_CLOSE_DATE, 'MON-YY')
ORDER BY
    TRUNC(RCA_CLOSE_DATE, 'MONTH')Doing the TRUNC in a subquery and formatting the result in the outer query as John has suggested may be more efficient.