topic Re: Difference in output when using WHERE statement on DATA line or below SET line in SAS Programming

Difference in output when using WHERE statement on DATA line or below SET line

Angmar — Mon, 19 Dec 2022 21:24:28 GMT

Hello,

I realised that the subset of data SAS creates when I use the WHERE statement in different lines is different.

For example, I often use:

DATA x (WHERE=(variable=1)

SET y

. . .

But I recently used

DATA x;

SET y;

WHERE=variable=1;

. . .

And the outputs were different. Would someone please explain to me why there is a difference?

Thank you.

Re: Difference in output when using WHERE statement on DATA line or below SET line

mtnbikerjoshua — Mon, 19 Dec 2022 21:34:25 GMT

Hi Angmar,

The difference there is that the first example, using where as a dataset option on the data statement, subsets the output dataset after all the processing in the data step has been done. The second example, using the where statement, subsets the input dataset(s) before all of the data processing. So, if the value of "variable" changes at all during the data step, the results of those two examples will be different.

Hope that explains it for you.

Joshua

Re: Difference in output when using WHERE statement on DATA line or below SET line

data_null__ — Mon, 19 Dec 2022 21:38:24 GMT

WHERE=variable=1;

When used in a data step is an assignment statement NOT a WHERE statement.

Try using valid syntax.

WHERE variable = 1;

Re: Difference in output when using WHERE statement on DATA line or below SET line

Angmar — Mon, 19 Dec 2022 21:40:55 GMT

Thank you very much! I understand now.