jq: select objects missing a specific attribute

jq_select_by_missing_attribute.sh

#!/bin/bash

set -euo pipefail

# Select all objects which do not contain an attribute named 'message'.
#
# Background: a log file contains messages from an application and
# numerous messages from Mongo db; the messages from Mongo contain
# an attribute called 'message', the application logs contain 'msg'
# instead. Filter the application logs only by selecting all objects
# which do not contain the 'message' attribute.
jq 'select(.message|not)' logs.json