I try to use SQL Developer to import data from csv file. At the Data Preview phrase, I adjust File Format. When I select or deselect Header，the first line in csv file is always treated as field name.
Very strange. What I see, in 17.3.1 as well as other earlier versions, is that unchecking the Header box changes the wizard page from
to
In your case, the COLUMN1, COLUMN2, ... line does not appear as it should at the top of the File Contents section. My test is on Windows 10. I see you use a different encoding and no enclosures. If you vary those options, does it make any difference?
Edit: Also, my file uses the file extension .csv, so Format defaults to csv and no adjustment is necessary. Do you use a different file extension and subsequently need to make an adjustment?
