Picking and Retaining another column value based on Changing Counter

[thepushkarsingh]

Is there an easy way to create WANT column with data having fields ID, DATE and HAVE column without using lag -

ID	DATE	Have	Want
A	30-Jun-06	1	30-Jun-06
A	31-Jul-06	1	30-Jun-06
A	31-Aug-06	1	30-Jun-06
A	30-Sep-06	1	30-Jun-06
A	31-Oct-06	1	30-Jun-06
A	30-Nov-06	0
A	31-Dec-06	0
B	30-Jun-06	0
B	31-Jul-06	0
B	31-Aug-06	0
B	30-Sep-06	0
B	31-Oct-06	1	31-Oct-06
B	30-Nov-06	1	31-Oct-06
B	31-Dec-06	1	31-Oct-06
C	30-Jun-06	0
C	31-Jul-06	1	31-Jul-06
C	31-Aug-06	1	31-Jul-06
C	30-Sep-06	0
C	31-Oct-06	0
C	30-Nov-06	1	30-Nov-06
C	31-Dec-06	1	30-Nov-06

[s_lassen · Accepted solution]

Something like this may work (not tested):

data data_want;
  set data_have;
  by id have notsorted;
  if first.have then do;
    if have=1 then want=date;
    else call missing(want);
    end;
  retain want;
run;

[thepushkarsingh]

Many thanks, that works!