Cannot add or update a child row: a foreign key constraint fails

Sorry, you need the namespace.

PHP Code:

Events::on(
    'DBQuery',
    static function (\CodeIgniter\Database\Query $query) { log_message('alert', (string) $query); }
); 


---

You can see the query in the error page.

ci-phpunit-test | CodeIgniter Testing Guide | CodeIgniter 3 to 4 Upgrade Helper