topic Re: Using Data Step how to update a Data Set based on comparison with another Data Set? in New SAS User

Using Data Step how to update a Data Set based on comparison with another Data Set?

manojsanthi — Tue, 02 Jul 2019 20:46:51 GMT

Hello,

I am new to SAS and to SAS Data Step. I want to know how I can update a Variable V1 in a Data Set A with the Value "Yes" whenever there is a match with Data Set B having a common Variable V2 between the 2 data sets?

Re: Using Data Step how to update a Data Set based on comparison with another Data Set?

Reeza — Tue, 02 Jul 2019 20:47:58 GMT

Depends on your data structure, but you can try a MERGE or UPDATE statement or MODIFY as starters.

Re: Using Data Step how to update a Data Set based on comparison with another Data Set?

manojsanthi — Tue, 02 Jul 2019 20:53:54 GMT

I read about Merge and Update, but I don't see how it can benefit my specific query as I am looking to enter a Constant String value in a Variable when ever there is a match in Values between 2 tables.

Re: Using Data Step how to update a Data Set based on comparison with another Data Set?

Reeza — Tue, 02 Jul 2019 20:54:42 GMT

Show an example of why you think it won't work.

Re: Using Data Step how to update a Data Set based on comparison with another Data Set?

Astounding — Tue, 02 Jul 2019 21:19:58 GMT

You're looking in the right direction. You need to add to what you have seen so far by adding IN= variables when you MERGE. For example:

data want;
   merge a (in=from_a) b (in=from_b);
   by V2;
   if from_a;
   if from_b then v1='Yes';
run;

This example assumes that both data sets are already in sortedf order by V2.