Wildcard input to output appended list

[clairel2018]

I currently have a wildcard input grabbing all files in a directory. I want to run it through my workflow and get a specific list, which I then want the workflow to continue to update (append existing output) when running the following file in directory. 

Examples: Say the workflow grabs value + 1

Input 1

1

2

3

Input 2

4

5

6

Expected Output

2

3

4

5

6

7

Output I got

5

6

7

I've tried using union to combine the iterative outputs, but since the input does not refresh/update, I'm still left with only the last input iteration. 

[Qiu]

@clairel2018 
I hope I understand what you need.
The same workflow will read every Excel file in the directory, assuming same Schema.

Then ouput the combined inputs to a data file, meaning read the last time saved datafile to compare with.

So you know which part is updated.

[clairel2018]

Hi, thanks so much for the sample solution! While I understand your base case and have played around with it a bit, I had a follow up questions: 

• Given that I want to run this wildcard/macro on more than 2 inputs (around 1000 actually) how would I go about updating the file that I want to replace in the macro? (I see that in the macro you outlined Excel1 as the input that I want to update and replace)

[Qiu]

@clairel2018 
Right click on the macro in the workflow and open the Macro in another Tab. Then modify the red part as you need.
The batch macro will read every Excel file in your specified direcory

.