cat_batch_insert.sh

cat /Users/valentinmouret/Desktop/users.csv \
| psql -c "

begin;

create temp table batch_user (
  id       text  primary key,
  document jsonb not null
);

copy batch_user (id, document)
-- We can run the same command but reading from standard input
-- intead of a file on the file system.
from STDIN
with (format 'csv',
      header,
      delimiter ',');

insert into user
            (id, email)
select batch_user.id,
       batch_user.document->>'email' as email
  from batch_user
       left join user
           using (id)
 where user.id is null
   and batch_user.document->>'email' is not null;

commit;"