並前往https://huskylin.github.io/2020/06/28/MySQL-%E5%9C%A8%E6%AF%8F%E5%80%8B%E7%BE%A4%E7%B5%84%E4%B8%AD%E5%8F%96-N-%E7%AD%86%E8%B3%87%E6%96%99-Get-1-N-Results-From-Each-Group/