ERROR: BY variables are not properly sorted on data set

[aelatova]

I am trying to combine 5 different data sets, and on the 5th one, it is saying I have an error that my BY variables are not sorted properly, even though I included PROC SORTS in the same way for each data set: 

PROC SORT DATA = HypImpt.UTAH_VITALS_2010 OUT= UTAH_VITALS_2010; 
	BY SSN ApptDate; 
	RUN; 
	
PROC SORT DATA = HypImpt.UTAH_VITALS_2011 OUT= UTAH_VITALS_2011; 
	BY SSN ApptDate; 
	RUN; 
	
PROC SORT DATA = HypImpt.UTAH_VITALS_2012 OUT= UTAH_VITALS_2012; 
	BY SSN ApptDate; 
	RUN; 
	
PROC SORT DATA = HypImpt.UTAH_VITALS_2013 OUT= UTAH_VITALS_2013; 
	BY SSN ApptDate; 
	RUN; 
	
PROC SORT DATA = HypImpt.UTAH_VITALS_2014 OUT= UTAH_VITALS_2014; 
	BY SSN ApptDate; 
	RUN; 


DATA	WORK.Vitals_UT;

	SET	HypImpt.UTAH_VITALS_2010
		HypImpt.UTAH_VITALS_2011
		HypImpt.UTAH_VITALS_2012
		HypImpt.UTAH_VITALS_2013
		HypImpt.UTAH_VITALS_2014;
    BY  SSN ApptDate; 
	
	RUN;

The error it gives me is 

ERROR: BY variables are not properly sorted on data set HYPIMPT.UTAH_VITALS_2014.

Any suggestions? 

[PaigeMiller]

The sorted data set is the OUT= data set.

So UTAH_VITALS_2014 is properly sorted, while HypImpt.UTAH_VITALS_2014 is not properly sorted.

[LinusH]

Hence, even if it's not required, it's good practive to wtite out 

work.

in all saswork table references.

By doing that, it's easier to spot these kind of logical errors in your code.

[Kurt_Bremser]

You can get this much easier:

data all / view=all;
set
  HypImpt.UTAH_VITALS_2010
  HypImpt.UTAH_VITALS_2011
  HypImpt.UTAH_VITALS_2012
  HypImpt.UTAH_VITALS_2013
  HypImpt.UTAH_VITALS_2014
;
run;

proc sort
  data=all
  out=Vitals_UT
;
by ssn apptdate;
run;