Hello,
I would like to know, if is it possible, that the component in the graph can fill the metadata itself?
For example, I want to duplicate some column (and I want to do it type independent). I want only to define metadata of input, then choose the column to duplicate. How to change metadata in the output edge without my intervent?
Do you have any suggestion, if is it possible and how to do it?
I hope, I describe my problem clear, please let me know, if it was incomprehensible.
Thanks
Jana
Hello Jana,
do you mean your custom component or any component?
In your component it is possible of course, but not in any component. It can be done in any component with transform attribute.
Hi Jana,
I would just add a little more details to Agata’s reply. The data transformation like adding new columns, removing the columns, applying calculations, etc. is specified in component’s Transformation attribute. If a particular component does not have transformation attribute (as Agata said, not all components do) then you need to include the Reformat component into your graph (dataflow).
For example, if you are reading the data from the input file and you would like to duplicate one of the columns, you need to include the Reformat component after the Reader component. In the Reformat component, you will most likely need to define a new metadata for the output (you can copy the input metadata and add one extra column) and implement the mapping between the input and output in the Transformation attribute.
The mapping can not only duplicate any column but also apply more complex calculations based on the record’s values using CTL2 language expression (e. g. concatenate two or more fields replace null values, etc.).
Hope that answers your question.