Filling empty cells with another column`s variable

[JibJam221]

Hi everyone, hoping to get some help on this one.

I have a table that holds customerIDs. There are two other columns called `dateofpurchase` and 'dateofvisit'. When 'dateofpurchase' is empty, im hoping to full these cells with the same 'dateofvisit' values, kind of like a default. However, if the 'dateofpurchase' is not empty, I want to keep it as is.

I do not have code to attach since I don't know where to start.

Thanks!

[Astounding]

Surely you could give us some sample data .... what it looks like before and what you want it to look like.  Be sure to include one example where a CustomerID is missing its very first dateofpurchase.

[ballardw]

One way  would look something like this:

data want;
   set have;
   if missing(dateofpurchase) then dateofpurchase=dateofvisit;
run;

The missing function tests a variable to see if it is missing and returns "true" (actually a numeric value of 1) when the variable does not have a value. If the variable is character consisting only of blanks it will also result in true.

[JibJam221]

thank you for this! Question - do you know if there is a way to do this for character variables as well?

[Phil_NZ · Accepted solution]

I think you can do

data want (rename(dateofpurchase1=dateofpurchase) drop=dateofpurchase1 );
   set have;
   dateofpurchase1= ifn(' ',dateofvisit,dateofpurchase)
run; 

And regarding the character value , you can change from "ifn" to "ifc" as @ballardw  mentioned.

More documents for you:

https://documentation.sas.com/?cdcId=pgmsascdc&cdcVersion=9.4_3.5&docsetId=lefunctionsref&docsetTarg...

https://documentation.sas.com/?cdcId=pgmsascdc&cdcVersion=9.4_3.5&docsetId=lefunctionsref&docsetTarg...

[ballardw]

---

@Phil_NZ wrote:

I think you can do

data want (rename(dateofpurchase1=dateofpurchase) drop=dateofpurchase1 );
   set have;
   dateofpurchase1= ifn(' ',dateofvisit,dateofpurchase)
run; 

And I think it can be applied for both numeric and character types of var.

---

Actually IFN works with numeric values. Character values require IFC.

[JibJam221]

thank you!

[JibJam221]

it works! Thank you x a million!

[andreas_lds]

---

@JibJam221 wrote:
thank you for this! Question - do you know if there is a way to do this for character variables as well?

---

The code posted by @ballardw works idependent of the variables' type. Both variables used in the assignment must have, of course, the same type.