## how to create a sequence number

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Super Contributor
Posts: 328

# how to create a sequence number

Hello

I have this data set;

data A;

cards;

001        2001

001        2002

001        2002

002        2001

002        2001

003        2002

;

run;

I wish to create data B from A

data B;

cards;

001        2001     1

001        2002     2

001        2002     3

002        2001     1

002        2001     2

003        2002     1

;

run;

I want to create a SeqN from Data A.

Accepted Solutions
Solution
‎05-10-2017 10:52 PM
Super User
Posts: 6,753

## Re: how to create a sequence number

As long as your data set is sorted by ID:

data want;

set have;

by id;

if first.id then SeqN=1;

else SeqN + 1;

run;

All Replies
Solution
‎05-10-2017 10:52 PM
Super User
Posts: 6,753

## Re: how to create a sequence number

As long as your data set is sorted by ID:

data want;

set have;

by id;

if first.id then SeqN=1;

else SeqN + 1;

run;

Super Contributor
Posts: 328

Thank you!!!

Super User
Posts: 9,599

## Re: how to create a sequence number

Good use for ifn()?

```data want;
set have;
by id;
seqn=ifn(first.id,1,seqn+1);
run;```
☑ This topic is solved.