Aggregates several columns into one single column.
In each row, it finds a matching column from the set of selected columns and places the name of that matching column into the aggregated result column. Which column matches depends on the selected "include method" and the include pattern.
If no column matches a missing value is added. If multiple columns match execution fails and no output is generated.
Missing values in the selected columns are ignored. If all selected columns of one row consist of missing values a missing value is put in the aggregated column. All include methods except the regular expression require columns which are double compatible.
- Type: TableData to processData