Date:         Mon, 9 Sep 2002 14:36:18 GMT
Reply-To:     julierog@ix.netcom.com
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Roger Lustig <trovato@BELLATLANTIC.NET>
Subject:      Re: merge
Content-Type: text/plain; charset=us-ascii; format=flowed

Kim:
If you sort the input files by ID and *descending* date, this becomes
much easier.

<assumption; file A has only one record per ID.>

<sort steps here>

data merged(keep=id date_b);
flag=0;
do until (last.id);
    merge a (rename=(date=date_a))
          b (rename=(date=date_b))
          ;
    by id;
    if date_a=date_b then flag=1;
    if flag=1 then output;
    end;
run;

<re-sort if need be>

kin tang wrote:
> Hello,
>
> I need to merge dataset A with dataset B by id and
> date. In the meantime,
> if there is a match, all earlier records prior to the
> matched date need
> to be retrieved as well.
>
> Data A
>
> id       date
>
> 123    15jan98
>
>
> Data B
>
> id       date
>
> 123    22oct96
> 123    12nov95
> 123    15jan98
> 123    29aug99
> 123    01jan00
>
> So the final dataset would be:
>
> Merged data
>
> id       date
>
> 123    22oct96
> 123    12nov95
> 123    15jan98
>
>
> How do I achieve this? Thanks.
>
>
> Kin
>
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