MySQL truncate table语句的使用
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 autocommit=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 | cc | 3 | 1 || 5 | dd | 1 | 2 || 6 | aac | 1 | 1 || 10 | a | 1 | 1 |+-----+-------+--------+---------+5 rows in set (0.00 sec)
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内容请搜索好吧啦网以前的文章或继续浏览下面的相关文章希望大家以后多多支持好吧啦网!
相关文章:
1. Mysql 获取表的comment 字段操作2. 启动MYSQL出错 Manager of pid-file quit without updating file.3. Mysql入门系列:MYSQL列类型选择与MYSQL查询效率4. Oracle根据逗号拆分字段内容转成多行的函数说明5. MySQL Community Server 5.1.496. 整理Oracle数据库碎片7. 让DB2数据库使用所有内存的方法(1)8. Mysql入门系列:MYSQL创建、删除、索引和更改表9. Access数据库安全的几个问题10. 恢复从 Access 2000、 Access 2002 或 Access 2003 中数据库删除表的方法

网公网安备