one to many merge

[xoxozav_1]

I am trying to merge 2 datasets using a by for the variables, but I am not sure if the method that I am using is the best method to perform One-to-many merge. I only want unique observations in the final dataset.

For example, I have 2 data sets, one called mother and other called children. So, one mother may have more than one child.

I started using :

PROC SORT DATA=mother nodupkey out=mother1;
BY v001 v002 ;
RUN;
proc sort data=children nodupkey out=children2;
by v001 v002 ;
run;
 Then I used this method :

data women1children3;
merge mother1 (in=ina) children2 (in=inb);
by v001 v002 v003;
if ina=inb;
run;

Is this method correct  for merging one to many, or should I use this one instead: (Defining the file with duplicates as a master)

data want ;
   merge master (in=in1) other ;
   by id;
   if in1 then output;
   in1=0;
run;

Thanks for the help!

[xoxozav_1]

I started using :

PROC SORT DATA=mother nodupkey out=mother1;
BY v001 v002 ;
RUN;
proc sort data=children nodupkey out=children2;
by v001 v002 ;
run;
 Then I used this method :

data women1children3;
merge mother1 (in=ina) children2 (in=inb);
by v001 v002 v003;
if ina=inb;
run;

Is this method correct  for merging one to many, or should I use this one instead: (Defining the file with duplicates as a master)

data want ;
   merge master (in=in1) other ;
   by id;
   if in1 then output;
   in1=0;
run;

Thanks for the help!

[Kurt_Bremser]

Since you use nodupkey in both sorts, it will be a 1:1 merge, and using v003 as third by variable in the merge is unnecessary.