Base SAS 9.1.3 Procedures Guide - Acsu Buffalo

314 APPEND Statement 4 Chapter 15
3 If formats in the DATA= data set are different from those in the BASE= data set,
then the formats in the BASE= data set are used. However, SAS does not convert
the data from the DATA= data set in order to be consistent with the formats in the
BASE= data set. The result could be data that appears to be incorrect. A warning
message is displayed in the SAS log. The following example illustrates appending
data by using different formats:
data format1;
input Date date9.;
format Date date9.;
datalines;
24sep1975
22may1952
;
data format2;
input Date datetime20.;
format Date datetime20.;
datalines;
25aug1952:11:23:07.4
;
proc append base=format1 data=format2;
run;
The following messages are displayed in the SAS log.
Output 15.2
Warning Message in SAS Log
NOTE: Appending WORK.FORMAT2 to WORK.FORMAT1.
WARNING: Variable Date has format DATE9. on the BASE data set
and format DATETIME20. on the DATA data set. DATE9. used.
NOTE: There were 1 observations read from the data set WORK.FORMAT2.
NOTE: 1 observations added.
NOTE: The data set WORK.FORMAT1 has 3 observations and 1 variables.
3 If the length of a variable is longer in the DATA= data set than in the BASE= data
set, or if the same variable is a character variable in one data set and a numeric
variable in the other, use the FORCE option. Using FORCE has these
consequences:
3 The length of the variables in the BASE= data set takes precedence. SAS
truncates values from the DATA= data set to fit them into the length that is
specified in the BASE= data set.
3 The type of the variables in the BASE= data set takes precedence. The
APPEND statement replaces values of the wrong type (all values for the
variable in the DATA= data set) with missing values.
Appending Data Sets That Contain Integrity Constraints
If the DATA= data set contains integrity constraints and the BASE= data set does
not exist, the APPEND statement copies the general constraints. Note that the
referential constraints are not copied. If the BASE= data set exists, the APPEND action
copies only observations.