SAS data step programming - sas

Question

I am new to SAS and I need some help here
The question below:
So far, I have done this:
data Purchase;
infile ‘c:\temp\PurchaseRecords.dat’ dlm=’,’ DSD;
input id $8 visit_no # unitpurchased #;
keep id unitpurchased;
run;
What do I need to add in my statement to make those orders look like this?
just an example.
Thank you.

Answer 1

You can use the infile column= in conjunction with the input held input # modifier to determine when held input has run past a trailing comma meant to indicate a missing value that is to be interpreted as a case of zero units_purchased. The automatic variable _infile_ is used to check when an input statement has positioned itself for the next read to be beyond the length of a data line.
data want;
infile datalines dsd dlm=',' column=p;
attrib id length=$8 units_purchased length=8 ;
input id #; * held input record;
* loop over held input record;
do while (p <= length(_infile_)+1); * +1 for dealing with trailing comma;
input units_purchased #; * continue to hold the record;
if missing(units_purchased) then units_purchased = 0;
output;
end;
datalines;
C005,3,15,,39
D2356,4,11,,5
A323,3,10,15,20
F123,1,
run;
The sometimes easier to use ## modifier wouldn't be used in this case because a missing value is to be considered valid input and thus can't be used to assert a 'no more data' condition.

Answer 2

Since the data includes the number of values use that to control a DO loop to read the values. I am not sure why you would want to lose the information on the order of the values, so I have commented out the KEEP statement. To convert the missing values to zeros I used a sum statement. You could use an IF/THEN statement or a COALESE() function call or other methods to convert the missing values to zeros.
data Purchase;
infile 'c:\temp\PurchaseRecords.dat' dsd truncover ;
length id $8 ;
input id visit_no # ;
do visit=1 to visit_no ;
input unitpurchased #;
unitpurchased+0;
output;
end;
* keep id unitpurchased;
run;
Your original program had a few errors:
Wrong quote characters. Use normal ASCII single or double quote characters.
It is reading value of ID from only column 8. I find it better to use LENGTH statement to define the variables instead of forcing SAS to guess at how to define the variables.
The input statement improperly is trying to use column pointer motion command, #nnn. Plus the variable location to move the pointer to, unitpurchased, has not yet been given a value.
No attempt was made to read more than one value from the line.
You did not include truncover (or even the older missover) option on your infile statement.