[v2] a debugging tip with Empty SQL vector expression

[randomwangran]

Just want to share my experience with V2 migration b183fd4.

If the file-level info is like this:

:PROPERTIES:
:ID:       15be2774-f063-40a3-a489-ab7e65ab54d9
:ROAM_ALIASES:
:END:
#+TITLE: C\+\+

Emacs will through an error, which is very hard to detect the cause.

emacsql-error: Invalid SQL statement: "Empty SQL vector expression."

:ROAM_ALIASES: is automatically generated by this script which was written by @jethrokuan with inputs from @d12frosted

Just make sure :ROAM_ALIASES: has something.

I spent a lot of time finding the root cause. I hope someone else can save a little bit of time just in case.

[d12frosted]

🤔 this script should not cause such problem because vulpea-buffer-prop-get and vulpea-buffer-prop-get-list return nil on empty values/strings. Though I am really curious, what was the original note that become malformed during migration process.

;; if roam_key is present but is empty, ROAM_REFS will not be create
(when-let* ((ref (vulpea-buffer-prop-get "roam_key")))
    (org-set-property "ROAM_REFS" ref)
    (let ((case-fold-search t))
      (org-with-point-at 1
        (while (re-search-forward "^#\\+roam_key:" (point-max) t)
          (beginning-of-line)
          (kill-line 1)))))

Usage example:

:PROPERTIES:
:ID:       15be2774-f063-40a3-a489-ab7e65ab54d9
:END:
#+TITLE: C\+\+
#+ROAM_ALIAS:

> (vulpea-buffer-prop-get "roam_alias")
nil

> (vulpea-buffer-prop-get-list "roam_alias")
nil

---

While I was writing this message, I realised that vulpea-buffer-prop-get still may cause a problem when you have an empty string of non-zero length (e.g. multiple trailing spaces). Fixed that in d12frosted/vulpea@f65671a

[randomwangran]

Hi @d12frosted :

Sorry for the delaying this response. V2 is so good that I enjoy it too much.

The migration was not smooth probably because I have some personal hooks in Org-mode. I remembered that I executed and killed the migration script a couple of times before the database was built. The root cause might be very hard to detect.

The migration script is good. I test it with the problematic file again. The :ROAM_ALIASES is successfully added to the :PROPERTIES: drawer.

(defun org-roam-v1-to-v2 ()
  ;; Create file level ID
  (org-with-point-at 1
    (org-id-get-create))
  ;; Replace roam_key into properties drawer roam_ref
  (when-let* ((refs (mapcan #'split-string-and-unquote
                            (cdar (org-collect-keywords '("roam_key"))))))
    (let ((case-fold-search t))
      (org-with-point-at 1
        (org-set-property "ROAM_REFS" (combine-and-quote-strings refs))
        (while (re-search-forward "^#\\+roam_key:" (point-max) t)
          (kill-line 1)))))

  ;; Replace roam_alias into properties drawer roam_aliases
  (when-let* ((aliases (mapcan #'split-string-and-unquote
                               (cdar (org-collect-keywords '("roam_alias"))))))
    (let ((case-fold-search t))
      (org-with-point-at 1
        (org-set-property "ROAM_ALIASES" (combine-and-quote-strings aliases))
        (while (re-search-forward "^#\\+roam_alias:" (point-max) t)
          (kill-line 1)))))

  ;; Replace #+roam_tags into #+filetags
  (org-with-point-at 1
    (let ((case-fold-search t))
      (while (search-forward "#+filetags:" nil t)
        (replace-match "#+filetags:" nil t))))
  (save-buffer))

P.s.: I also enjoy your blog about dynamic agendas. It is really cool!

Thanks for your contribution @d12frosted and the community. I really appreciate it.