sql order by 多个列

项目有个小需求，需要用到 排序，但是是一个表里的，多个字段。。。

所以，就google了

这里有一段，写的很好，

摘自

INPUT

SELECT prod_id, prod_price, prod_name FROM Products ORDER BY prod_price, prod_name;

OUTPUT

prod_id  prod_price  prod_name
-------  ----------  --------------------
BNBG02   3.4900      Bird bean bag toy
BNBG01   3.4900      Fish bean bag toy
BNBG03   3.4900      Rabbit bean bag toy
RGAN01   4.9900      Raggedy Ann
BR01     5.9900      8 inch teddy bear
BR02     8.9900      12 inch teddy bear
RYL01    9.4900      King doll
RYL02    9.4900      Queen doll
BR03     11.9900     18 inch teddy bear

It is important to understand that when you are sorting by multiple columns, the sort sequence is exactly as specified. In other words, using the output in the example above, the products are sorted by the prod_name column only when multiple rows have the same prod_price value. If all the values in the prod_price column had been unique, no data would have been sorted by prod_name.