这里是动物生日,按日期排序:
mysql> SELECT name, birth FROM pet ORDER BY birth; +----------+------------+ | name | birth | +----------+------------+ | Buffy | 1989-05-13 | | Bowser | 1989-08-31 | | Fang | 1990-08-27 | | Fluffy | 1993-02-04 | | Claws | 1994-03-17 | | Slim | 1996-04-29 | | Whistler | 1997-12-09 | | Chirpy | 1998-09-11 | | Puffball | 1999-03-30 | +----------+------------+
在字符类型列上,与所有其他比较操作类似,分类功能正常情况下是以区分大小写的方式执行的。这意味着,对于等同但大小写不同的列,并未定义其顺序。对于某一列,可以使用BINARY强制执行区分大小写的分类功能,如:ORDER BY BINARY col_name.
默认排序是升序,最小的值在第一。要想以降序排序,在你正在排序的列名上增加DESC(降序 )关键字:
mysql> SELECT name, birth FROM pet ORDER BY birth DESC; +----------+------------+ | name | birth | +----------+------------+ | Puffball | 1999-03-30 | | Chirpy | 1998-09-11 | | Whistler | 1997-12-09 | | Slim | 1996-04-29 | | Claws | 1994-03-17 | | Fluffy | 1993-02-04 | | Fang | 1990-08-27 | | Bowser | 1989-08-31 | | Buffy | 1989-05-13 | +----------+------------+
可以对多个列进行排序,并且可以按不同的方向对不同的列进行排序。例如,按升序对动物的种类进行排序,然后按降序根据生日对各动物种类进行排序(最年轻的动物在最前面),使用下列查询:
mysql> SELECT name, species, birth FROM pet -> ORDER BY species, birth DESC; +----------+---------+------------+ | 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 | | Puffball | hamster | 1999-03-30 | | Slim | snake | 1996-04-29 | +----------+---------+------------+
注意DESC关键字仅适用于在它前面的列名(birth);不影响species列的排序顺序。