mybatis Example Criteria like 模糊查询问题

  TestTableExample example = new TestTableExample();
  example.createCriteria().andField1EqualTo(5);

 TestTableExample example = new TestTableExample();
  example.or().andField1EqualTo(5);

where field1 = 5

TestTableExample example = new TestTableExample();

  example.or()
    .andField1EqualTo(5)
    .andField2IsNull();

  example.or()
    .andField3NotEqualTo(9)
    .andField4IsNotNull();

  List<Integer> field5Values = new ArrayList<Integer>();
  field5Values.add(8);
  field5Values.add(11);
  field5Values.add(14);
  field5Values.add(22);

  example.or()
    .andField5In(field5Values);

  example.or()
    .andField6Between(3, 7);

     where (field1 = 5 and field2 is null)
     or (field3 <> 9 and field4 is not null)
     or (field5 in (8, 11, 14, 22))
     or (field6 between 3 and 7)

        PageHelper.startPage(pageNum,pageSize);
        TbBrandExample example = new TbBrandExample();
        TbBrandExample.Criteria criteria = example.createCriteria();
        if (tbBrand != null) {
            if (tbBrand.getName() != null && tbBrand.getName().length()>0) {
                criteria.andNameLike("%"+tbBrand.getName()+"%");
            }
            if (tbBrand.getFirstChar() != null && tbBrand.getFirstChar().length()>0) {
                criteria.andFirstCharLike("%"+tbBrand.getFirstChar()+"%");
            }
        }
        Page<TbBrand> page = (Page<TbBrand>) brandMapper.selectByExample(example);
        return new PageResult((int) page.getTotal(),page.getResult());