PostgreSQL resolv El valor duplicado viola la restricción única
SELECT setval(pg_get_serial_sequence('users', 'id'), coalesce(max(id)+1, 1), false) FROM users;
Tiago F2
SELECT setval(pg_get_serial_sequence('users', 'id'), coalesce(max(id)+1, 1), false) FROM users;
SELECT setval('the_primary_key_sequence', (SELECT MAX(the_primary_key) FROM the_table)+1);