PkfieldsExample example = new PkfieldsExample();
List<Pkfields> answer = mapper.selectByExample(example);
assertEquals(2, answer.size());
example = new PkfieldsExample();
example.createCriteria().andLastnameLike("J%");
int rows = mapper.deleteByExample(example);
assertEquals(1, rows);
example = new PkfieldsExample();
answer = mapper.selectByExample(example);