关于MYSQL中order排序的问题

Question

SELECT roomno,type,price from room where price<='100'order by roomno desc,price desc 关键是最后一局，倒出来的结果只显示 roomno desc，不显示price desc 我知道mysql不支持循环，但这个问题怎么解决呢？

Answer 1

出现这种情况那说明roomno的一列数据都不相同，如果price的一列有相同的数据，那应改为：
SELECT roomno,type,price
from room
where price<='100'
order by price,roomno DESC;
如下例：
SELECT name, species, birth FROM pet
ORDER BY species, birth DESC;
结果为：
name | species | birth |

+----------+---------+------------+

| Chirpy | bird | 1998-09-11 |

| Whistler | bird | 1997-12-09 |

| Claws | cat | 1994-03-17 |

| Fluffy | cat | 1993-02-04 |

| Fang | dog | 1990-08-27 |

| Bowser | dog | 1989-08-31 |

| Buffy | dog | 1989-05-13 |

 

Answer 2

SELECT roomno,type,price
from room
where price<='100'
order by roomno,price desc