SAS "Set" statement when combining two data sets

[jc3992]

Hello everyone,

I am doing some SAS certificate questions, and I have run the code below,

and got the different answer as it provided with on the Internet.

The code is as follows:

DATA work.first;
  Input common $ X;
  cards;
  A 10
  A 13
  A 14
  B 9
  ;
  run;
  
DATA work.second;
  input common $ Y;
  cards;
  A 1
  A 3
  B 4
  B 2
  ;
  run;
  
data work.combine;
  SET work.first;
  set work.second;
  run;
  
  

The question is: what data values are stored in data set work.combine?

The answer is :

common X Y 

A             10 1

A             13 3

B             14 4

B              9  2

But my result when I tested it in SAS is:

common X

A            10

A            13

A            14

B              9

Would anyone tell me which is the correct?

Thank you very much!!

[Reeza]

---

@jc3992 wrote:

Hello everyone,

I am doing some SAS certificate questions, and I have run the code below,

and got the different answer as it provided with on the Internet.

The code is as follows:

DATA work.first;
  Input common $ X;
  cards;
  A 10
  A 13
  A 14
  B 9
  ;
  run;
  
DATA work.second;
  input common $ Y;
  cards;
  A 1
  A 3
  B 4
  B 2
  ;
  run;
  
data work.combine;
  SET work.first;
  set work.second;
  run;
  
  

The question is: what data values are stored in data set work.combine?

The answer is :

common X Y 

A             10 1

A             13 3

B             14 4

B              9  2

But my result when I tested it in SAS is:

common X

A            10

A            13

A            14

B              9

Would anyone tell me which is the correct?

Thank you very much!!

---

Post your log. I ran the exact code and get a different output. I suspect you've named them both X instead of X and Y? 

[jc3992]

1          OPTIONS NONOTES NOSTIMER NOSOURCE NOSYNTAXCHECK;
 72         
 73         DATA work.first;
 74           Input common $ X;
 75           cards;
 
 NOTE: The data set WORK.FIRST has 4 observations and 2 variables.
 NOTE: DATA statement used (Total process time):
       real time           0.00 seconds
       cpu time            0.01 seconds
       
 
 80           ;
 81           run;
 82         
 83         DATA work.second;
 84           input common $ Y;
 85           cards;
 
 NOTE: The data set WORK.SECOND has 4 observations and 2 variables.
 NOTE: DATA statement used (Total process time):
       real time           0.00 seconds
       cpu time            0.01 seconds
       
 
 90           ;
 91           run;
 92         
 93         data work.combine;
 94           SET work.first;
 95           set work.second;
 96           run;
 
 NOTE: There were 4 observations read from the data set WORK.FIRST.
 NOTE: There were 4 observations read from the data set WORK.SECOND.
 NOTE: The data set WORK.COMBINE has 4 observations and 3 variables.
 NOTE: DATA statement used (Total process time):
       real time           0.00 seconds
       cpu time            0.00 seconds
       
 
 97         
 98         
 99         
 100        OPTIONS NONOTES NOSTIMER NOSOURCE NOSYNTAXCHECK;
 113        

[Reeza]

The log says 4 obs and 3 variables which doesn't match what you posted, since it had only one variable. 

I still think the answer from my initial post is what happened. 

---

@jc3992 wrote:

1          OPTIONS NONOTES NOSTIMER NOSOURCE NOSYNTAXCHECK;
 72         
 73         DATA work.first;
 74           Input common $ X;
 75           cards;
 
 NOTE: The data set WORK.FIRST has 4 observations and 2 variables.
 NOTE: DATA statement used (Total process time):
       real time           0.00 seconds
       cpu time            0.01 seconds
       
 
 80           ;
 81           run;
 82         
 83         DATA work.second;
 84           input common $ Y;
 85           cards;
 
 NOTE: The data set WORK.SECOND has 4 observations and 2 variables.
 NOTE: DATA statement used (Total process time):
       real time           0.00 seconds
       cpu time            0.01 seconds
       
 
 90           ;
 91           run;
 92         
 93         data work.combine;
 94           SET work.first;
 95           set work.second;
 96           run;
 
 NOTE: There were 4 observations read from the data set WORK.FIRST.
 NOTE: There were 4 observations read from the data set WORK.SECOND.
 NOTE: The data set WORK.COMBINE has 4 observations and 3 variables.
 NOTE: DATA statement used (Total process time):
       real time           0.00 seconds
       cpu time            0.00 seconds
       
 
 97         
 98         
 99         
 100        OPTIONS NONOTES NOSTIMER NOSOURCE NOSYNTAXCHECK;
 113        

---

[Astounding]

The answer is correct.  Somehow, the program you tested is different than the one in the practice exam.

Incidentally, is this a SAS provided practice exam?  It would be highly unusual for SAS to add a RUN statement after a CARDS statement.

[jc3992]

The data sets were from my own creation. 

SAS did not give me the code to produce the data sets.

Thank you very much for your help!

[ballardw · Accepted solution]

This code duplicates your stated output:

DATA work.first;
  Input common $ X;
  cards;
  A 10
  A 13
  A 14
  B 9
  ;
  run;
  
DATA work.second;
  input common $ x;
  cards;
  A 1
  A 3
  B 4
  B 2
  ;
  run;
  
data work.combine;
  SET work.second;
  set work.first;
  run;

Note that the work.second has the same variable name X instead of Y and the order of the two set statements is different.

[jc3992]

DATA work.first;
  Input common $ X;
  cards;
  A 10
  A 13
  A 14
  B 9
  ;
  run;
  
DATA work.second;
  input common $ Y;
  cards;
  A 1
  A 3
  B 4
  B 2
  ;
  run;
  
data work.combine;
  SET work.first;
  set work.second;
  run;
  

This was what I used to run the command earlier. Sorry after adding "Proc Print data=work.combine;"

I found it was because of the screen blocking the other half of the output.

Thank you very much!!