Chris Cormack a écrit :
On Mon, Mar 07, 2005 at 07:18:05PM -0500, Stephen Hedges said:
Chris' solution still won't give you an accurate issue date, since he presumes that people renew items on the date_due -- and we all know that borrowers are not that dependable (damn!). Adding the issue_date to the issues table seems to be the only way to get an accurate statistic.
Yep it makes that assumption it also makes the assumption that none of the due_dates have been overriden (which you can do in circulation). I think it may be the only way to get an approximation of the average loan length with the data as it stands.
Going forward we should add an issue_date column to the table, if that is useful data to know.
I'm curious, Henri-Damien -- are you trying to do a daily statistics report? Is that why you need the issue date?
I think he is trying to work out average loan length, which would be an interesting statistic to know. Daily stats you can figure out from the statistics table.
Chris
Utterly right. I was asked to work on statistic reports, more precisely on issues stats to provide the operator with average loan length over a period. Daily statistics has already been coped with. Have a nice day. -- Henri-Damien LAURENT