Issue with many-to-one merge

[ivadc]

Hello, I'm trying a simple many-to-one merge but I'm getting weird results.

In the program below, I want to replace 6 & 8 by 3, and 4 & 7 by 5. However, only the 6 and 4 are being replaced. Any ideas?

data master;
input CPI NAPCS;
cards;
1 6
1 8
2 4
2 7
;
data updates;
input CPI NAPCS;
cards;
1 3
2 5
;

data master2;
merge master updates;
by CPI;
run;

Please, no SQL suggestions.

[ghosh · Accepted solution]

data master2;
merge master(drop=napcs) updates;
by CPI;
run;

proc print; run;