I am using MySQL 4.0.22 and have a question about an efficient way to calculate
a running balance as part of the select. The natural way to do this would seem
(to me) to be something like:
set @balance:=0;
select payid,Custid,Paid,@balance:[EMAIL PROTECTED] from payments;
This does indeed seem to work. However the way I read the explanation on user
variables I would not expect this to work. I found a solution for this from the
MySQL Cookbook using a self join which for the above would be:
select t1.payid,t1.Custid,t1.user,t1.Paid,sum(t2.Paid)
from payments as t1, payments as t2
where t1.payid>=t2.payid group by t1.payid;
This also works but as I am sure most of you know will not scale to even a
few thousand records.
Will using the user variable work? If not where might I find some
alternate techniques?
_____
Douglas Denault
http://www.safeport.com
[EMAIL PROTECTED]
Voice: 301-469-8766
Fax: 301-469-0601
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