Consider this context :
I have a table which I use everyday containing column A, B, C.
New customer need, column D needs to be added.
I proced with an altair sql command and fill the previous values stated at NULL to empty strings (because D is a string type column).
For now, all works properly, I still have all my data and my newest column D.
But now, as I said in first place, I am using this table with a scenario reporter wich append new lines every day.
And when I want to test it, running manually the scenario, the table remains but with only the new line, all the previous data collected with only columns A, B, C are deleted.
! SOS !