Average for last 12 months

Question

hi,
i have a column amount. i need to find the avg of it for last 12 months excluding current month.
I have got a query to find it .but it is adding current month also with it.
AVG(SUM(amount)) OVER (ORDER BY ACCOUNT_MONTH_NO
ROWS BETWEEN 12 PRECEDING AND 0 FOLLOWING) rolling_avg,
please help me to write a query as i am a naive user of oracle.

Answer 1

Like..
SQL> select * from test;
ACCOUNT_NU ACCOUNT_MONTH_NO     AMOUNT
ACC1                      1        100
ACC1                      2        200
ACC1                      3        300
ACC1                      4        400
ACC1                      5        500
ACC1                      6        600
ACC1                      7        700
ACC1                      8        800
ACC1                      9        900
ACC1                     10       1000
ACC1                     11       1100
ACC1                     12       1200
12 rows selected.
SQL> select account_month_no,amount,
  2     avg(amount) over(order by account_month_no rows
  3            between 12 preceding and 1 preceding) avg
  4  from test
  5  where ACCOUNT_NUMBER  = 'ACC1';
ACCOUNT_MONTH_NO     AMOUNT        AVG
               1        100
               2        200        100
               3        300        150
               4        400        200
               5        500        250
               6        600        300
               7        700        350
               8        800        400
               9        900        450
              10       1000        500
              11       1100        550
              12       1200        600
12 rows selected.Post sample data and expected output, so that we can help you better