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Alteryx designer Discussions

Find answers, ask questions, and share expertise about Alteryx Designer.

Tell User If Expected Columns Are Undetected


Hello Alteryx Community.  Back with yet. another. question!  Is there a way to tell a user, when running an app, that columns expected in order for the workflow to go through are missing from the input data set?  To add another step, what about telling the user that there are columns in the data set that were not expected?  Thanks :0) 

Alteryx Certified Partner
Alteryx Certified Partner

Hi Robert, this is a great question!


Firstly you will need to create a list of your desired field names. I have then joined this against a field into tool to understand what fields are mising before using an error message tool to pass these to the end user.


Attached is an example.




Hi Robert,


That is a great question. I believe you are asking about metadata being different from expected, and not blank rows. The following workflow can help get you started with turning those missing fields and unexpected fields into their own streams. As an example, I put message tools on the outputs to warn me once the workflow / analytic app is ran.


metadata input.PNGExpected Columns 
Data Input.PNGActual Inputworkflow_to_create_errors.PNGCreate messages from metadata changes




When ran as an analytic app, these are how the messages appear:



I should mention that most tools will raise an error or warning (depending on how critical) when a needed column is missing, so the approach above is sometimes unnecessary.

For example, if a column is missing from what a predictive model is expecting, it will send an error anyway. If the column wasn't selected for the model when creating the workflow, however, it will continue without error.



- Joe





Thank you for your responses.  This information will help me a lot!!