select varibles from two dataset

[lulu3]

Hi expert,

I had several datasets. Some datasets only contains thru_dt, and some datasets contains both from_dt and thru_dt. I wanted to select

a). if the dataset only contains thru_dt, then select '01JAN2015'd <=thru_dt<='05JAN2015'd,

b). if the dataset contains both from_dt and thru_dt, then select '01JAN2015'd <=from_dt<='05JAN2015'd.

For example:

data one;
input id $ thru_dt:mmddyy10.;
format thru_dt mmddyy10.;
datalines;
1 01/01/2015
2 01/02/2015
3 01/03/2015
4 01/04/2015
5 01/05/2015
6 01/06/2015
7 01/07/2015
;
run;

data two;
input id $ from_dt:mmddyy10. thru_dt:mmddyy10.;
format from_dt thru_dt mmddyy10.;
datalines;
1 01/01/2015 01/02/2015
2 01/02/2015 01/03/2015
3 01/03/2015 01/03/2015
4 01/04/2015 01/04/2015
5 01/05/2015 01/05/2015
6 01/06/2015 01/06/2015
7 01/07/2015 01/07/2015
;
run;

I tried the following codes, but it said ERROR: Variable from_dt is not on file WORK.ONE.

data want;
set one two;
where '01JAN2015'd <=from_dt<='05JAN2015'd | '01JAN2015'd <=thru_dt<='05JAN2015'd;
run;

Any suggestions would be greatly appreciated!

[ChrisNZ · Accepted solution]

Like this?

data WANT;
 set ONE TWO;
 where '01JAN2015'd <= coalesce(from_dt,thru_dt) <= '05JAN2015'd ;

run;