need to add new row in existing dataset

[vraj1]

Attached data. what i need is if PDCTREAS(resons for withdrawal is present then add a row in desc and desc_fmt and value for treatment as 1 . i am trying the below code but it doesnt work.

if PDCTREAS ne "" then do;
desc= "ByPrim";
dsreas_num_trt= 1;
dsreas_fmt = " "||PDCTREAS;
sort1 = 88;
output;
end;

[Patrick]

@vraj1

Without looking into the attached data set I believe what you're missing is an OUTPUT statement.

/* option 1 */
data old;
  set old;
  OUTPUT;
  if <some condition> then
    do;
      varA=1;
      ...
      OUTPUT;
    end;
run;

/* option 2: "better" */
data new_stuff;
  set old;
  if <some condition> then
    do;
      varA=1;
      ...
      OUTPUT;
    end;
run;

proc append base=old data=new_stuff;
run;

[vraj1]

If i use the condition 

if PDCTREAS ne "" then do;  then it removes everything which is missing but i need all the data and add new variables.

I am not able to find out a way

[Patrick]

@vraj1

That's why you need a first OUTPUT statement right after the SET statement. This will write all observations from the input data set directly to the output data set.

Then comes your condition. Whenever the condition is TRUE you're doing additional variable assignments and then you're issuing an additional OUTPUT statements which writes another row to the output table.

... or even better: Just collect all new rows into a table and then append this table to your original data set (that's Option 2).

[PrathameshP]

proc sql;
create table WANT like HAVE;
quit;

proc sql; insert into WANT (var1, var2, var3)
values (123,'ABC','01JAN2020'D)
values (456,'EFG','20NOV2020'D);
quit;

[mkeintz]

@PrathameshP 

Your suggestion won't work.  The inserts need to be conditioned on some comparison.