difference between SET and APPEND

[rawindar]

Can anybody tell me the differnces between SET and APPEND.Thanks in advance

[sambasiva_ravuri_tcs_com]

SET statement is used to read Input/Records.

APPEND is A proc in SAS.

PROC APPEND BASE=SAS-data-set DATA=SAS-data-set;
RUN;
where
BASE=SAS-data-set
names the data set to which you want to add observations.
DATA=SAS-data-set
names the SAS data set containing observations that you want to append to the end of the
SAS data set specified in the BASE= argument.

PROC APPEND reads only the data in the DATA= SAS data set, not the BASE= SAS
data set. PROC APPEND concatenates data sets even though there may be variables in
the BASE= data set that do not exist in the DATA= data set.
When the BASE= data set contains more variables than the DATA= data set, missing
values for the additional variables are assigned to the observations that are read in
from the DATA= data set and a warning message is written to the SAS log.

Let me know if you have any questions.

Regards,

S Ravuri.

[ballardw]

Proc Append won't add any variables that do not exist in the base dataset. However it is faster for adding records than using SET in a datastep.

[rawindar]

thank....u.I have one doubt we can add any no of datasets at a time.In the same way is can we add more than one datasets at a time using APPEND .I tried but i didnt get is there any way.

If we wanna do append using APPEND/SET there must be same variables names,with out a same variable names we cant append is this right?

Thanks & regards

Rawindarreddy

[chirag_sachdeva]

You can use a macro to append multiple datasets together using PROC APPEND.

But SET statement will do the trick without the macro as well.

It'll take a little bit of time to code the macro but overall efficiency of the MACRO will be better compared to SET statement with multiple datasets.

(PS: I know this post is way too old)

[Hima]

http://www.albany.edu/~msz03/epi514/notes/p121_142.pdf