Date:         Mon, 16 Nov 2009 12:49:35 -0600
Reply-To:     Joe Matise <snoopy369@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Joe Matise <snoopy369@GMAIL.COM>
Subject:      Re: Comparing Dates From 2 Different Files
Comments: To: David Friedman <harrypotterdhf@earthlink.net>
In-Reply-To:  <200911161752.nAGHIYFd011920@malibu.cc.uga.edu>
Content-Type: text/plain; charset=ISO-8859-1

Something like this should work.  No promise about speed, but it should
function.

data have;
informat date1 MMDDYY8.;
format date1 mmddyy8.;
input CustomerID             date1;
datalines;
1                      01/06/09
1                      02/07/09
1                   03/08/09
1                      04/08/09
1                      04/15/09
1                      05/01/09
2                      02/01/09
2                      06/01/09
2                      08/02/09
;;;;
run;
data to_merge;
informat date1 MMDDYY8.;
format date1 mmddyy8.;
input CustomerID             date1;
datalines;
1                      03/07/09
1                      04/09/09
1                      04/30/09
2                      03/06/09
2                      07/07/09
;;;;
run;

proc sql;
create table want as
    select h.customerID, h.date1, min(t.date1) as new_date
        from have h, (
            select m.customerid,m.date1,h.date1 as cur_date
                from have h, to_merge m
                where m.customerid=h.customerid
                    and m.date1 >= h.date1
            ) t
        where h.customerid=t.customerid and h.date1=t.cur_date
        group by h.customerID, h.date1
        having min(t.date1-h.date1);
quit;

-Joe

On Mon, Nov 16, 2009 at 11:52 AM, David Friedman <
harrypotterdhf@earthlink.net> wrote:

> Thanks, Toby. I forgot to add the stipulation that the date from the 2nd
> file can not be earlier than the date from the 1st file.
>