Sometimes, rather than just combining
data from two data sets, you might want to update the data in one
data set with data that is stored in another data set. That is, you
might want to update a master data set by overwriting certain values
with values that are stored in a transaction data set.
For example, suppose
the data set Mylib.Empmaster contains data that is outdated. The current
data is stored in another data set named Mylib.Empchanges. Mylib.Empmaster
contains 148 observations, and Mylib.Empchanges contains six observations.
The variable EmpID contains unique values in both data sets.
A partial listing of Mylib.Empmaster and the full listing of Mylib.Empchanges is shown below. Notice that there ...