Date:         Tue, 1 Jul 2008 17:35:07 -0500
Reply-To:     Mary <mlhoward@avalon.net>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Mary <mlhoward@AVALON.NET>
Subject:      Re: Update info in data set based on other data set
Content-Type: text/plain; charset="iso-8859-1"

Jan,

Ian is correct that I'm not accounting for possible duplicate values in the lookup table.

Here's a nested join solution, using the second table as a lookup;  I'll think about whether I can improve upon it, but it does seem to work.

-Mary

data test1;

infile cards;

input id visit mmddyy10.;

format visit mmddyy10.;

cards;

1 06/12/2008

1 06/13/2008

3 06/14/2008

;

data test2

infile cards;

input id visit mmddyy10.;

format visit mmddyy10.;

cards;

1 06/12/2008

1 06/12/2008

3 06/13/2008

;

proc sql;

select test1.*, 1 as flag

from test1

where test1.id in (select test2.id

from test2 where test1.id=test2.id

and test1.visit=test2.visit)

union

select test1.*, 0 as flag

from test1

where test1.id not in (select test2.id

from test2 where test1.id=test2.id

and test1.visit=test2.visit);

quit;

run;