Removing duplicates (with criteria)

[zizou1845]

Hi All, I have a data that looks something like this:

Group     Year           Frequency

A            2010               5

A            2010               5

A            2010               5

B            2012               6

B            2012               6

B            2012               6

C            1999               1

C            1999               1

My question is, how do i remove duplicates so that it looks like this:

Group       Year           Frequency

A              2010               5

B              2012               6

C              1999               1

Thank You.

[Haikuo]

Well, there are numerous methods that are cut for this kind of task:

1. Proc sort:

proc sort data=have out=want nodup;

by _all_;

run;

2. Proc SQL:

proc sql;

create table want as

select distinct * from have; quit;

3. First.var and Last.var.

data want;

set have;

  by id notsorted;

if first.id;

run;

4.  Hash(), given the question you have asked, I would recommend you get to know the first three options before trying to tackle hash()

Regards,

Haikuo