ADF is changing the expression when I save

Question

Hi everyone
I'm trying to write locals to save some expression I'm using.
ADF completely screw it up by changing it as soon as I save it. It does the same if I try with column
Below are some screenshots if I try with column:

Then, I click on "Save" at the top right corner, and "save and finish" at the bottom left corner
Then, i reopen

What is happening? I tried to open a new window, I tried to refresh the page. Nothing. It just breaks. Is it a bug because it goes above the max length of expression? What is the max length of expression?
thank you.

Answer 1

Hi V ,

Welcome to Microsoft Q&A platform and thanks for posting your query here.

As I understand it correctly, you are using mapping dataflow in ADF and trying to write an expression to generate hash code for the combination of columns in the source dataset. However, the expression is not getting saved properly.

I believe you are using 'Derived column transformation' for writing the above expression and the source type looks like json file? Kindly confirm if that is correct assumption.

It seems the issue is because of the file type being in the complex form. Could you please try to flatten the data using flatten transformation and then try to use derived column transformation to generate the hash code using the simplified schema and see if works fine or not. I tried to reproduce the scenario for simple schema and it works well. Additionally, sha2 doesn't accept the array , you need to provide all the column names individually comma separated and not as an array[] :

Hope it helps. Kindly let me know how it goes. Thankyou