1. 命令語法：delete from 表名 where 表達式

實踐：

（1）刪除表student中編號為3的記錄

mysql> use zbf
Database changed
mysql> select * from student;
+----+-----------+-----+--------+
| id | name  | age | dept   |
+----+-----------+-----+--------+
|  1 | zbf666|  29 | linux  |
|  2 | lisi  |  28 | mysql  |
|  3 | zhangsan  |  21 | python |
|  4 | woshishei |  24 | java   |
+----+-----------+-----+--------+
4 rows in set (0.06 sec)

mysql> delete from student where id=3;
Query OK, 1 row affected (0.01 sec)

mysql> select * from student;
+----+-----------+-----+-------+
| id | name  | age | dept  |
+----+-----------+-----+-------+
|  1 | zbf666|  29 | linux |
|  2 | lisi  |  28 | mysql |
|  4 | woshishei |  24 | java  |
+----+-----------+-----+-------+
3 rows in set (0.02 sec)
 

（2）也可以刪除name等於lisi的行

mysql> select * from student;
+----+-----------+-----+-------+
| id | name  | age | dept  |
+----+-----------+-----+-------+
|  1 | zbf666|  29 | linux |
|  2 | lisi  |  28 | mysql |
|  4 | woshishei |  24 | java  |
+----+-----------+-----+-------+
3 rows in set (0.02 sec)

mysql> delete from student where name=‘lisi‘;
Query OK, 1 row affected (0.01 sec)

mysql> select * from student;
+----+-----------+-----+-------+
| id | name  | age | dept  |
+----+-----------+-----+-------+
|  1 | zbf666|  29 | linux |
|  4 | woshishei |  24 | java  |
+----+-----------+-----+-------+
2 rows in set (0.00 sec)
 

（3）也可以刪除id大於3的行

mysql> select * from student;
+----+-----------+-----+-------+
| id | name  | age | dept  |
+----+-----------+-----+-------+
|  1 | zbf666|  29 | linux |
|  4 | woshishei |  24 | java  |
+----+-----------+-----+-------+
2 rows in set (0.00 sec)

mysql> delete from student where id>3;
Query OK, 1 row affected (0.01 sec)

mysql> select * from student;
+----+--------+-----+-------+
| id | name   | age | dept  |
+----+--------+-----+-------+
|  1 | zbf666 |  29 | linux |
+----+--------+-----+-------+
1 row in set (0.00 sec)
 

提示：不加條件就是全部刪除，也是非常危險的操作，這裏接不演示了。delete from student 。

2.命令語法Truncate table 表名

Truncate table student; 清空表中所欲內容

mysql> truncate table student;
Query OK, 0 rows affected (0.00 sec)

mysql> select * from student;
Empty set (0.00 sec)

Truncate from srudent和delete from student區別

a.Truncate table student;更快，清空物理文件。

b.delete from student;邏輯清除，按行刪。

Mysql DBA 高級運維學習筆記-刪除表中數據