SAS: Data Step Merge example

Source:

* Merge example ;

data a;

input key1 key2 aonly both;

datalines;

1 1 1 1

1 2 2 2

3 1 3 3

3 2 6 6

5 1 5 5

;

run;

data b;

input key1 key2 bonly both;

datalines;

1 2 8 22  expect change var both from 2 to 22

3 3 8 3   expect insert

5 1 8 55  expect change var both from 5 to 55

;

run;

data merged;

merge a b;

by key1 key2;

run;

proc print data=merged;

run;

Results:

Obs	key1	key2	aonly	both	bonly
1	1	1	1	1	.
2	1	2	2	22	8
3	3	1	3	3	.
4	3	2	6	6	.
5	3	3	.	3	8
6	5	1	5	55	8