我建了一个表 如图 mysql> select * from libraryloan;
+----+--------+------+------------+------+
| id | member | book | dueDate | fine |
+----+--------+------+------------+------+
| 1 | jim | NULL | NULL | NULL |
| 2 | tom | NULL | 2008-11-14 | NULL |
| 3 | tom | NULL | 2008-11-28 | NULL |
| 4 | jim01 | bk02 | 2008-11-28 | NULL |
+----+--------+------+------------+------+ 如何同时删除多行呢?如我想同时删除book,fine两列
+----+--------+------+------------+------+
| id | member | book | dueDate | fine |
+----+--------+------+------------+------+
| 1 | jim | NULL | NULL | NULL |
| 2 | tom | NULL | 2008-11-14 | NULL |
| 3 | tom | NULL | 2008-11-28 | NULL |
| 4 | jim01 | bk02 | 2008-11-28 | NULL |
+----+--------+------+------------+------+ 如何同时删除多行呢?如我想同时删除book,fine两列
drop column book,
drop column fine;