Re: array of arrays calculations

in reply to array of arrays calculations

Why not just do the calculation right in the SQL?

select h.cus, 
       h.ta,
       h.gd1 - c.gd1 as diff1,
       h.gd2 - c.gd2 as diff2,
       from hist h, hist c
 where h.cus = c.cus
   and h.ta = c.ta 
 order by h.cus, h.ta
[download]

WARNING: not tested! YMMV!

What can be asserted without proof can be dismissed without proof. - Christopher Hitchens

In Section Seekers of Perl Wisdom