Hi David, On 13/09/2023 02:16 CEST David E. Wheeler <da...@justatheory.com> wrote:
> CREATE TABLE MOVIES (id SERIAL PRIMARY KEY, movie JSONB NOT NULL); > \copy movies(movie) from PROGRAM 'curl -s > https://raw.githubusercontent.com/prust/wikipedia-movie-data/master/movies.json > | jq -c ".[]" | sed "s|\\\\|\\\\\\\\|g"'; > create index on movies using gin (movie); > analyze movies; > > I have been confused as to the difference between @@ vs @?: Why do these > return different results? > > david=# select id from movies where movie @@ '$ ?(@.title == "New Life > Rescue")'; > id > ---- > (0 rows) > > david=# select id from movies where movie @? '$ ?(@.title == "New Life > Rescue")'; > id > ---- > 10 > (1 row) > > I posted this question on Stack Overflow > (https://stackoverflow.com/q/77046554/79202), > and from the suggestion I got there, it seems that @@ expects a boolean to be > returned by the path query, while @? wraps it in an implicit exists(). Is that > right? That's also my understanding. We had a discussion about the docs on @@, @?, and jsonb_path_query on -general a while back [1]. Maybe it's useful also. > If so, I’d like to submit a patch to the docs talking about this, and > suggesting the use of jsonb_path_query() to test paths to see if they return > a boolean or not. +1 [1] https://www.postgresql.org/message-id/CACJufxE01sxgvtG4QEvRZPzs_roggsZeVvBSGpjM5tzE5hMCLA%40mail.gmail.com -- Erik
