1、修改table name：
mysql>alter table ?teacher ?rename tomaster;
Query OK, 0 rows affected (0.11 sec)
2著榴、添加列：
mysql>alter table ?master ?add column ?salary double;
Query OK, 0 rows affected (0.61 sec)
Records: 0? Duplicates: 0? Warnings: 0
3颅和、刪除列：
mysql>alter table ?master ?drop column ?test;
Query OK, 0 rows affected (0.60 sec)
Records: 0? Duplicates: 0? Warnings: 0
4元莫、修改列名：
mysql>alter table ?master ?change ?test tel int(13);
Query OK, 0 rows affected (0.08 sec)
Records: 0? Duplicates: 0? Warnings: 0
修改前列名：
修改后列名：
