Question

To archive the DONE tasks i am using

C-c C-x a

command. The draw back is i have to manually move over the DONE tasks one by one and then archive it.

How to archive all the DONE tasks using a single command.

Answer 1

You can write a function using org-map-entries:

(defun my-org-archive-done-tasks ()
  (interactive)
  (org-map-entries 'org-archive-subtree "/DONE" 'file))