Creating a formula based on a column existing or not

[nbryanrh]

Hi All,

I am quite new to this community, having an issue processing a report whose column might differ on every run. For example:

Col A	Col B	Col C
ABC	DEF	GHI

Sometimes all three columns exist, or sometimes only column B exists, etc.

I'd like to create a new column with the following logic:

IF (col A exists) THEN [col A]

ELSEIF (col B exists) THEN [col B]

ELSEIF (col C exists) THEN [col C]

ELSE null( )

ENDIF

For example, if only Col B & Col C exists, the value taken should be from Col B. How would this be possible? Thanks for your help!

[Qiu · Accepted solution]

@nbryanrh 
I think we need to "force" all the column to be present even when they are not. 😀

I created another input file which contains only all the columns then do a union/