Problem(s) with One2Many


I’m getting the following error with One2Many:

ERROR One2Many Configure failed (IllegalArgumentException): Duplicate column name “” at positions 56 and 60.

Note that I already have the Domain Calculator fronting One2Many. I thought One2Many was supposed to handle duplicate cells in a given column…


Hi Paul,

this happens because one column name is equal to the value of one of the columns.

e.g. you have column A with values (A,B,B,A) , then a colum A is also created as a binary value column. But this is not possible.

The handling of this kind of duplicate column is not implemented currently.

As a workaround rename your columns before e.g. with the Column Rename (Regex) node.


Hi Iris,


The problem was the data cells had information with some cells having leading/trailing spaces and other cells didn't.

So 'A' and ' A ' were present. This caused the error.

Just a follow-up. We fixed the problem and the fix will be available in 2.10.

Credit goes to Iris.