選取表的信息：
+--------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------+-------------+------+-----+---------+-------+
| number | char(11) | YES | | NULL | |
| name | varchar(50) | YES | | NULL | |
| age | int(11) | YES | | NULL | |
+--------+-------------+------+-----+---------+-------+
+--------+--------+------+
| number | name | age |
+--------+--------+------+
| 1 | java | 18 |
| 2 | c | 19 |
| 1 | python | 18 |
| 1 | cpp | 18 |
+--------+--------+------+
刪除指定行
語法：DELETE FROM 表名
WHERE ···;
輸入語句：
mysql> DELETE FROM tb_stu
-> WHERE name='cpp';
運行結果：
Query OK, 1 row affected (0.00 sec)
查看錶中各行的值：
+--------+--------+------+
| number | name | age |
+--------+--------+------+
| 1 | java | 18 |
| 2 | c | 19 |
| 1 | python | 18 |
+--------+--------+------+
刪除全部行
語法：DELETE FROM 表名;
輸入語句：
mysql> DELETE FROM tb_stu;
運行結果：
Query OK, 3 rows affected (0.00 sec)
查看錶中各行的值：
Empty set (0.00 sec)
刪除時記得加WHERE，否則手抖就會把所有行給清空了！！