MyBatis多参数问题(@Param和arg和param)

三者等价

@Repository
public interface UserMapper {
    @Select("SELECT * FROM user WHERE username=#{username} AND age=#{age}")
    public User findUser01(@Param("username") String username, @Param("age") Integer age);

    @Select("SELECT * FROM user WHERE username=#{arg0} AND age=#{arg1}")
    public User findUser02(String username,Integer age);

    @Select("SELECT * FROM user WHERE username=#{param1} AND age=#{param2}")
    public User findUser03(String username,Integer age);
}