Logseq journal: On this day

Recently I moved my journals to Logseq and I like it very much. I use it almost everyday now. Core features are good, and the plugins market place surpasses my expectation.

Oh and I’ve written journals for the last 6 years, sometimes I want to know on this day of some years before, what was happenning and what was I thinking. Lo and behold, Logseq has advanced queries feature for just that!

Create new page and paste this content into it:

#+BEGIN_QUERY
{:title "On this day some years before"
 :query [:find (pull ?b [*])
       :in $ ?today
       :where
       [?b :block/page ?p]
       [?p :page/journal-day ?d]
       [(str ?d) ?ds]
       [(subs ?ds 4 8) ?md1]
       [(str ?today) ?td]
       [(subs ?td 4 8) ?md2]
       [(= ?md1 ?md2)]
       [(< ?d ?today)]
]
:inputs [:today]}
#+END_QUERY

Logseq use Datascript for database and Datalog for query engine. What I’ve done above can be translated to normal language as:

• Scan all pages, in each page, get the journal date attribute.
• Convert that attribute to string, you will get something like “20220225” which is in “yyyyMMdd” format.
• Take just the “MMdd” part, and compare that part with today’s “MMdd”.
• Return all blocks that match today’s and having the date less than today.