SAS query

[scb]

DATASET A

CASE    DATE                  CUST    STATUS

A1        01JAN1990        123       NEW

A2        02JAN1990        290       NEW

DATASET B

CASE    DATE                  CUST    STATUS

A3        01FEB1990         380      NEW

A4        02FEB1990         490      NEW      

A5        02FEB1990         290      OLD

A6        03FEB1990         490      OLD

There are 2 monthly datasets.The customer status was determined by the DATE.  If the CUST appears first time then categorized as NEW customer. 

If the customer appears in the same month, the first record will be categorized as NEW and subsequent will be as OLD.

Anyone can help? Thanks.

[LinusH]

You need to append the data sets. Then sort and use BY/first. logic.

[PoojaP1]

You need to check the observations by using BY statement/cust.first and date.first (to check if that particular customer appeared first time on that date).

[Kurt_Bremser]

Customer 290 does not meet your rule for "OLD" in observation 3 of dataset B. It is the first appearance in the month of February.

Quote:

"If the customer appears in the same month, the first record will be categorized as NEW and subsequent will be as OLD."

[Ksharp]

What does DATASET A stands for ? Does DATASET A contain cust which all are status=new /

data A;
input (CASE    DATE                  CUST    STATUS) (:$20.);
cards;
A1        01JAN1990        123       NEW
A2        02JAN1990        290       NEW
;
data B;
input (CASE    DATE                  CUST   ) (:$20.);
cards;
A3        01FEB1990         380    
A4        02FEB1990         490         
A5        02FEB1990         290    
A6        03FEB1990         490  
;
run;

data want;
 if _n_=1 then do;
  if 0 then set a;
  declare hash h(dataset:'a');
  h.definekey(key:'cust');
  h.definedone();
 end;
set b;
if h.check()=0 then status='old';
 else do;status='new';h.add();end;
run;