Currently, there is not a way to append to a file. Here is an idea to vote for to encourage the developers: https://community.tableau.com/ideas/8823
Also, Tableau Prep does not allow you to use a file for input and output in the same flow. I'm guessing there are specific reasons for this, but it does create a limitation in how you can address the issue you mentioned.
There are several possibilities that come to mind.
- I have seen someone mention using an Excel file to automatically import the contents of an output file and using that Excel file as an input. I couldn't find the thread or blog post right off and don't remember the specifics, but that might be one approach.
- Another possibility is to copy the output file for use as an input as you described in your question. You might even find a utility that automatically makes a copy of the file to a known location.
- One other possibility would be to place each new XLSX file in the same directory and then union them together to recreate the final output each time.
Each of those options have potential positives and drawbacks, but hopefully gives you some idea about how you might want to approach a solution.
Thanks Joshua! I would love to see this fixed!
In the meantime, I'll have to use Windows Explorer to move the output file to replace the input file. That's easier than VBA macros or 3rd party automation software,