QueryWrapper<Student> queryWrapper = new QueryWrapper<>();
Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String format = sdf.format(date);
queryWrapper.lambda()
        .eq(Student::getName, "小芳")
        .eq(Student::getSex, "女")
        .le(Student::getStartTime,format)
        .ge(Student::getEndTime,format);

List<Student> students= studentMapper.selectList(queryWrapper);