mybatis使用注解的方式实现简单的crud

在对应的Mapper接口中编写：

//查询所有
@Select("select * from mybatis.user")
List<User> getUsers();

//通过性别查询
@Select("select * from mybatis.user where sex=#{sex}")
List<User> getUserBySex(@Param("sex")String sex);

//添加
@Insert("insert into mybatis.user values(#{username},#{pswd},#{sex})")
int addUser1(User user);

//通过username删除
@Delete("delete from mybatis.user where username = #{username}")
int delByUsername1(@Param("username")String username);

//通过username修改
@Update("update mybatis.user set sex=#{sex} where username = #{username}")
int update1(User user);

编写测试java代码进行测试：

@Test
public void selAlls(){ //查询所有
   SqlSession sqlSession = MybatisUtils.getSqlSession();
   UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
   List<User> users = userMapper.getUsers();
   for(User user:users){
       System.out.println(user);
   }
   sqlSession.close();
 }
@Test //查询通过Sex
public void getUserBySex(){
    SqlSession sqlSession = MybatisUtils.getSqlSession();
    UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
    List<User> users = userMapper.getUserBySex("男");
    for(User user:users){
        System.out.println(user);
    }
    sqlSession.close();
}
@Test
public void addUser1(){ //添加
    SqlSession sqlSession = MybatisUtils.getSqlSession();
    UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
    userMapper.addUser1(new User("hahaha","psw123","女"));
    sqlSession.commit();
    sqlSession.close();
}
 @Test
 public void delByUsername1(){ //通过username删除
    SqlSession sqlSession = MybatisUtils.getSqlSession();
    UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
    userMapper.delByUsername1("hahaha");
    sqlSession.commit();
    sqlSession.close();
}
@Test
public void update1(){ //修改
    SqlSession sqlSession = MybatisUtils.getSqlSession();
    UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
    userMapper.update1(new User("小张","aabb1122","男"));
    sqlSession.commit();
    sqlSession.close();
}

@Param()，只要是传递基本数据类型，建议都加上。