Unknown Field in Select Tool

[CMorg16]

What is the purpose of the Unknown Field? How would this impact my workflow if I leave it checked/unchecked?  

[Armon24 · Accepted solution]

The Dynamic/Unknown field (column) shows up and is checked by default in the configuration properties of the Select tool (as well as other tools).

The purpose of this field is to allow new fields to come in, in cases where your input file might change. It gives you the ability to determine where new fields go in the file by moving the field's position.

https://help.alteryx.com/20223/designer/troubleshooting-and-faq 

[ThomasT]

Hi there,

If you leave it checked and 'New Fields' come in through your data flow the select tool will let the 'New Fields' flow through. 

If you de-select the 'Unknown Fields' it will not allow 'New Fields' to flow through the select tool and only stream out those fields which were previously checked. 

Similar principle across multiple tools within Alteryx eg Cross-Tab/Transpose.

[PanPP]

Hi @CMorg16 

The *Unknown represents any fields that may come into the tool which it did not know about when the module was originally built. If it’s selected then any new fields from the data stream will continue downstream for further processing and perhaps be included in outputs, if deselected then any new fields will be dropped. Generally you probably pay little attention to this and generally, it won’t really affect your processing, but there are occasions when it can be quite useful.

Please take a look at this article for more details.

Hope this helps, if it does please like this post and if it helps resolve your problem, mark it as a solution. If you have any other questions, please let us know.

[Krishnasn]

Hi @ThomasT, @Armon24 

On selecting the Unknown fields option, the new fields show up in the downstream tools, but when we want to use them in downstream tools, they have to be checked manually. DO we have any shortcut to check all of them at once instead of going to each tool and enabling them?

Thanks,

Krishna

[flying008]

Hi, @Krishnasn 

If you want to automatically select all new field columns in the downstream tool, it depends on whether your downstream tool has the *Unknown Field* selection option. In any case, unless you are sure that the new data field columns generated after the data source changes will not cause unexpected troubles to your workflow logic, manual selection is a safe approach.

[Krishnasn]

Hi @flying008 

Yes definitely, it is safe to keep the "unknown field" unselected to avoid unexpected changes in the downstream.

But I was wondering if there is a way, while editing the workflow, to bring in new fields at the input and propagate them to downstream tools in a single click or some setting instead of opening every tool and checking the boxes for the new fields?

Thanks,

Krishna

[flying008]

Hi, @Krishnasn 

As far as I know, there is no such option as you mentioned, because many tools are not as simple as the Select tool in that the selection of field columns is either this or that. Especially for tools like Summarize, how do you let the tool decide whether to put the new field column in the Group item or the Calculate item?
So if you really want to implement the full process dynamic selection of field columns in the workflow, you might as well upload your workflow or take a screenshot to express your needs, maybe there is a workaround that can achieve your expectations.

[Krishnasn]

Hi @flying008,

You are right. There are some tools that need manual intervention to configure fields and some do not.

I have found an idea that was submitted requesting for the same functionality - Link

The purpose of it could be to use when we have lengthy workflow and we are sure that the downstream tools would just need to be populated with new fields. This type of a feature exists in like ETL tools - Informatica. 

Thanks for your inputs. Appreciate it!

Best,

Krishna

[flying008]

Hi, @Krishnasn 

Since Alteryx has not yet implemented similar functions to INFORMATICA, I would like to mention it above. If possible, please use a simple case and screenshots to illustrate your needs. Because before this, other posts mentioned the need to dynamically update the selection of field columns. I have used dynamic select tool and dynamic replace tool to automatically update calculations to achieve their intended purpose.