SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE pid <> pg_backend_pid() AND datname = 'db_name';
# Works for psql 12
select pg_terminate_backend(pid) from pg_stat_activity where datname='<db_name>';
SELECT
pg_terminate_backend(pid)
FROM
pg_stat_activity
WHERE
pid <> pg_backend_pid()
AND datname = 'database_name';