Merging a Repeated Measures data set with a non repeated measures data set

[ajb]

Merging a Repeated Measures data set with a non repeated measures data set 

Hi All,

I have 2 data sets 

example.new, the repeated measures data set

example.old,  the non repeated measures data set

I am trying to create a data set that included arm and has the same observations as the non repeated data set.

/*new data set with new variable -arm*/

data work.arm;

      set example.new;

      keep id  arm;

run;

proc sort data=work.arm;

      by id;

run;

proc sort data=example.old;

      by id;

run;

data example.arm;

      merge work.arm

         example.old(in=A);

   by id;

   if A=1 ;

run;

 The problem is that this code does not work.  The following is from the log. 

NOTE: There were 3487 observations read from the data set WORK.ARM.

NOTE: There were 706 observations read from the data set example.old

NOTE: The data set example.arm has 2120 observations and 29 variables.

NOTE: DATA statement used (Total process time):

     real time          4.25 seconds

     cpu time           0.04 seconds

I want example.arm to have the same 706 observations as example.old but it keeps giving me 2120 observations.

[Reeza]

When merging with the repeated measures data set, which record do you want to join with?

Generally if dealing with many to one I prefer to use SQL, and this would be a LEFT join.

[PGStats]

Try 

if A and first.id;

as your merge step condition.