how do you sum over a related period

I need to sum values that are + 2 months or within a quarter period (related date table)

is there a way开发者_JAVA技巧 to use dense rank to partition those periods (custom periods)?

select
FiscalMonth
,Value
from table

The sql will have to do the following:

1. Join the value table and the period table
2. Include the period in the select list and sum the value, grouping by the period

i.e

 select b.period, sum(a.value)
  from table a 
    inner join period b on a.FiscalMonth between b.StartMonth and b.EndMonth
     group by b.period

Note: The join condition will have to be modified based on what data you actually have in the period table.

Hope this helps

Well, If you need value from an X interval, by month you could use something like:

SELECT *
FROM yourTable
    MONTH(some_date) = MONTH(CURRENT_DATE - INTERVAL 1 MONTH)  //Could be X interval!

This is an example (which show the results of the previous month, from the actual one). Just trying to write that it is possible to massage the query in functions on intervals.

Of course, you could use the SUMcommand for the adding.