In SAS, how do I merge two data sets?
To merge two or more data sets in SAS, you must first sort
both data sets by a shared variable upon which the merging will be
based. Then, use the MERGE statement in your
DATA statement.
If you merge data sets without sorting, called one-to-one merging, the data of the merged file overwrites the primary data set without considering whether or not two observations are the same.
For example, suppose you have two data sets (one and
two below), with a common variable, id. The
SAS codes below show how they can be sorted and merged:
In the example above, data set three is created by
merging data sets one and two. It will have
five variables (id, and v1 to
v4) and four cases. Where id=4, variables
v1 and v2 will be missing.
For more information about statistical and mathematical software, email the UITS Stat/Math Center, visit the center's web page, or phone 812-855-4724 (IUB) or 317-278-4740 (IUPUI). The center is located in Bloomington at 410 N. Park Avenue, and is open for consultation by appointment Monday-Friday 9am-5pm.
Last modified on January 02, 2009.
