MySQL truncate table语句的使用

网络编程 2021-07-05 14:37www.168986.cn编程入门
这篇文章主要介绍了MySQL truncate table语句的使用,文中通过示例代码介绍的非常详细,对大家的学习或者工作具有一定的参考学习价值,需要的朋友们狼蚁网站SEO优化随着长沙网络推广来一起学习学习吧

Truncate table语句用来删除/截断表里的所有数据

  • 和delete删除所有表数据在逻辑上含义相同,但性能更快
  • 类似执行了drop table和create table两个语句

执行代码

mysql> select  from students_bak;
+-----+----------+--------+---------+
| sid | sname | gender | dept_id |
+-----+----------+--------+---------+
| 101 | zhangsan | male |  10 |
| 1 | aa  | 1  |  1 |
+-----+----------+--------+---------+
2 rows in set (0.00 sec)

mysql> truncate table students_bak;
Query OK, 0 rows affected (0.16 sec)

mysql> select  from students_bak;
Empty set (0.00 sec)

mysql> set automit=off;
Query OK, 0 rows affected (0.01 sec)

mysql> select  from students3;
+-----+-------+--------+---------+--------+
| sid | sname | gender | dept_id | sname2 |
+-----+-------+--------+---------+--------+
| 100 | NULL | 1  |  1 | NULL |
+-----+-------+--------+---------+--------+
1 row in set (0.01 sec)

mysql> truncate table students3;
Query OK, 0 rows affected (0.06 sec)

mysql> rollback;
Query OK, 0 rows affected (0.00 sec)

mysql> select  from students3;
Empty set (0.00 sec)

mysql> delete from students;
Query OK, 5 rows affected (0.00 sec)

mysql> select  from students;
Empty set (0.00 sec)

mysql> rollback;
Query OK, 0 rows affected (0.07 sec)

mysql> select  from students;
+-----+-------+--------+---------+
| sid | sname | gender | dept_id |
+-----+-------+--------+---------+
| 1 | aa | 3  |  1 |
| 4 |  | 3  |  1 |
| 5 | dd | 1  |  2 |
| 6 | aac | 1  |  1 |
| 10 | a  | 1  |  1 |
+-----+-------+--------+---------+
5 rows in set (0.00 sec)

truncate需要什么权限

truncate的执行是先drop后create的, 所以truncate包含drop和create,是一个复合的动作, 对于create不用赋予, 所以只需要赋予drop权限就可以了

到此这篇关于MySQL truncate table语句的使用的文章就介绍到这了,更多相关MySQL truncate table内容请搜索狼蚁SEO以前的文章或继续浏览狼蚁网站SEO优化的相关文章希望大家以后多多支持狼蚁SEO!

Copyright © 2016-2025 www.168986.cn 狼蚁网络 版权所有 Power by