Multiple To clauses in Data step - sas

Question

I have a data step where I have a few columns that need tied to one other column.
I have tried using multiple "from" statements and " to" statements and a couple other permutations of that, but nothing seems to do the trick. The code looks something like this:
data analyze;
set css_email_analysis;
from = bill_account_number;
to = customer_number;
output;
from = bill_account_number;
to = email_addr;
output;
from = bill_account_number;
to = e_customer_nm;
output;
run;
I would like to see two columns showing bill accounts in the "from" column, and the other values in the "to", but instead I get a bill account and its customer number, with some "..."'s for the other values.

Answer 1

Issue
This is most likely because SAS has two datatypes and the first time the to variable is set up, it has the value of customer_number. At your second to statement you attempt to set to to have the value of email_addr. Assuming email_addr is a character variable, two things can happen here:
Customer_number is a number - to has already been set up as a number, so SAS cannot force to to become a character, an error like this may appear:
NOTE: Invalid numeric data, 'me#mywebsite.com' , at line 15 column 8. to=.
ERROR=1 N=1
Customer_number is a character - to has been set up as a character, but without explicitly defining its length, if it happens to be shorter than the value of email_addr then the email address will be truncated. SAS will not show an error if this happens:
Code:
data _NULL_;
to = 'hiya';
to = 'me#mydomain.com';
put to=;
run;
short=me#m
to is set with a length of 4, and SAS does not expand it to fit the new data.
Detail
The thing to bear in mind here is how SAS works behind the scenes.
The data statement sets up an output location
The set statement adds the variables from first observation of the dataset specified to a space in memory called the PDV, inheriting lengths and data types.
PDV:
bill_account_number|customer_number|email_addr|e_customer_nm
===================================================================
010101 | 758|me#my.com |John Smith
The to statement adds another variable inheriting the characteristics of customer_number
PDV:
bill_account_number|customer_number|email_addr|e_customer_nm|to
===================================================================
010101 | 758|me#my.com |John Smith |758
(to is either char length 3 or a numeric)
Subsequent to statements will not alter the characteristics of the variable and SAS will continue processing
PDV (if customer_number is character = TRUNCATION):
bill_account_number|customer_number|email_addr|e_customer_nm|to
===================================================================
010101 | 758|me#my.com |John Smith |me#
PDV (if customer_number is numeric = DATA ERROR, to set to missing):
bill_account_number|customer_number|email_addr|e_customer_nm|to
===================================================================
010101 | 758|me#my.com |John Smith |.
Resolution
To resolve this issue it's probably easiest to set the length and type of to before your first to statement:
data analyze;
set css_email_analysis;
from = bill_account_number;
length to $200;
to = customer_number;
output;
...
You may get messages like this, where SAS has converted data on your behalf:
NOTE: Numeric values have been converted to character
values at the places given by: (Line):(Column).
27:8
N.B. it's not necessary to explicitly define the length and type of from, because as far as I can see, you only ever get the values for this variable from one variable in the source dataset. You could also achieve this with a rename if you don't need to keep the bill_account_number variable:
rename bill_account_number = from;