public class User extends Model<User> {}

public void testSelectById(){  
    User user = new User();  
    user.setId(16L);  
   
    User user = user.selectById();  
}

public void testInsert(){  
    User user = new User();  
    user.setUserName("diaochan");  
    user.setPassword("123456");  
    user.setAge(20);  
    user.setName("貂蝉");  
    user.setMail("diaochan@itcast.cn");  
    user.setVersion(1);  
    user.setSex(SexEnum.WOMAN); //使用的是枚举  
  
    // 调用AR的insert方法进行插入数据  
    boolean insert = user.insert();  
    System.out.println("result => " + insert);  
}

public void testUpdate(){  
    User user = new User();  
    user.setId(13L);// 查询条件  
    user.setAge(31); // 更新的数据  
  
    boolean result = user.updateById();  
    System.out.println("result => " + result);  
}

public void testDelete(){  
    User user = new User();  
    user.setId(13L);  
  
    boolean delete = user.deleteById();  
    System.out.println("result => " + delete);  
}

public void testSelect(){  
    User user = new User();  
  
    QueryWrapper<User> wrapper  = new QueryWrapper<>();  
    wrapper.ge("age", 30); //大于等于30岁的用户查询出来  
  
    List<User> users = user.selectList(wrapper);  
    for (User user1 : users) {  
        System.out.println(user1);  
    }
}