SAS: Combining two data sets with different format - merge

Question

I have two datasets that are formatted differently
data1 looks like:
data1:
YYMM test1
1101 98
1102 98
1103 94
1104 92
1105 99
1106 91
data 2 is just a single grand mean that looks like:
data2:
GM
95
I would like to combine the two and have something that looks like this:
WANT:
YYMM test1 GM
1101 98 95
1102 98 95
1103 94 95
1104 92 95
1105 99 95
1106 91 95
I'm sure there are different ways to go about configuring this but I thought I should make the 95 into a column and merge with data1.
Do I have to use macro for this simple task? Please show me some light!

Answer 1

One straightforward way is to just merge without by statement and the use of retain:
data WANT (drop=temp);
merge DATA1 DATA2 (rename=(GM=temp));
retain GM;
if _N_=1 then GM=temp;
run;
So basically you put the two datasets together.
Because there is no by-statement, it will join together the first record of both datasets, the second record of both datasets and so on.
At the first record (if N=1), you grab the average and you put it in a variable for which the last value will be remembered (retain GM).
So in record 2, 3 etc, the value will still be what you put into it at record 1.
To keep it all clean, i renamed your GM variable on the input, so it was available to use as name for the retained variable. And of course, i dropped the redundant variable.
You can also approach this issue with a macro variable or a proc sql. But better keep it simple.

Answer 2

Here's a similar way that's slightly simpler.
data want;
set data1;
if _n_=1 then set data2;
run;