KEEP= Data Set Option
For an input data set, specifies the variables to
process; for an output data set, specifies the variables to write
to the data set.
| Valid in: |
DATA step and PROC steps |
| Category: |
Variable Control |
Syntax
KEEP=variable-1
<...variable-n>
Syntax Description
- variable-1 <...variable-n>
-
lists one or more variable
names. You can list the variables in any form that SAS allows.
Details
If the KEEP= data set
option is associated with an input data set, only those variables
that are listed after the KEEP= data set option are available for
processing. If the KEEP= data set option is associated with an output
data set, only the variables listed after the option are written to
the output data set. All variables are available for processing.
Comparisons
-
The KEEP= data set option differs
from the KEEP statement in the following ways:
-
In DATA steps, the KEEP= data set
option can apply to both input and output data sets. The KEEP statement
applies only to output data sets.
-
In DATA steps, when you create
multiple output data sets, use the KEEP= data set option to write
different variables to different data sets. The KEEP statement applies
to all output data sets.
-
In PROC steps, you can use only
the KEEP= data set option, not the KEEP statement.
-
The DROP= data set option specifies
variables to omit during processing or to omit from the output data
set.
Example
In this example, only
IDNUM and SALARY are read from PAYROLL, and they are the only variables
in PAYROLL that are available for processing:
data bonus;
set payroll(keep=idnum salary);
bonus=salary*1.1;
run;