MySQL中表的复制以及大型数据表的备份教程
表复制
mysql拷贝表操作我们会常常用到，下面就为您详细介绍几种mysql拷贝表的方式，希望对您学习mysql拷贝表方面能够有所帮助。
假如我们有以下这样一个表：
id username password ----------------------------------- 1 admin ************* 2 sameer ************* 3 stewart *************
CREATE TABLE IF NOT EXISTS `admin` ( `id` int(6) unsigned NOT NULL auto_increment, `username` varchar(50) NOT NULL default '', `password` varchar(100) default NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=4 ;
1. 下面这个语句会拷贝表结构到新表newadmin中。 （不会拷贝表中的数据）
CREATE TABLE newadmin LIKE admin
2. 下面这个语句会拷贝数据到新表中。 注意：这个语句其实只是把select语句的结果建一个表。所以newadmin这个表不会有主键，索引。
CREATE TABLE newadmin AS ( SELECT * FROM admin )
3. 如果你要真正的复制一个表。可以用下面的语句。
CREATE TABLE newadmin LIKE admin; INSERT INTO newadmin SELECT * FROM admin;
4. 我们可以操作不同的数据库。
CREATE TABLE newadmin LIKE shop.admin; CREATE TABLE newshop.newadmin LIKE shop.admin;
5. 我们也可以拷贝一个表中其中的一些字段。
CREATE TABLE newadmin AS ( SELECT username, password FROM admin )
6. 我们也可以讲新建的表的字段改名。
CREATE TABLE newadmin AS ( SELECT id, username AS uname, password AS pass FROM admin )
7. 我们也可以拷贝一部分数据。
CREATE TABLE newadmin AS ( SELECT * FROM admin WHERE LEFT(username,1) = 's' )
8. 我们也可以在创建表的同时定义表中的字段信息。
CREATE TABLE newadmin ( id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY ) AS ( SELECT * FROM admin )
MySQL大表备份
这里所说的大表是超过4G以上的表,我目前见到过最大为６０多Ｇ的单表，对于这种表每天一个全备可以说是一件很痛苦的事。
那么有没有办法，可以实现一个全备加增量的备份呢。
答案当然是有的。
在常规环境直可以用全备加binlog一同保存。
这种环境大多可以用一个Slave上进行备份操作。
思路：
先停止Slave的同步，刷新buffer，对于Innodb 如果想直接拷贝还需要把innodb_max_dirty_pages_pct这个值置为零，然后在执行一次flush tables;
就可以cp了。如果是Dump出来可以这这样做。
这个方案目前来看也是比较完美的，但一个并发力度大的应用一天的Binlog有可能能达到５０G－６０G，这样的系统开Binlog可以说是对系统的ＩＯ性能及整体性能都有早影响。
另一种方案就是基于表的上数据的罗辑变化进行备份。
主体思想：全备加逻辑备份。
逻辑备份：当有数据插入时，利用触发器同时写入另一个表，当数据更新时，我们同时记录一下，更新后的数据情况到另一个表。
当有删除操作时，只需要记录一下，删除的主建ＩＤ就行。
例子：
要备份的表：
CREATE TABLE `wubx` ( `id` int(11) NOT NULL auto_increment, `user_id` int(11) NOT NULL default '0', `friend_id` int(11) NOT NULL default '0', `dir_id` int(11) NOT NULL default '0', `created` int(11) NOT NULL default '0', UNIQUE KEY `id` (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;
对于这个表我们需要建一个记录有新数据变化的表为：
mysql> create table wubx_ii like wubx; Query OK, 0 rows affected (0.00 sec) mysql> create table wubx_uu like wubx; Query OK, 0 rows affected (0.00 sec) mysql> create table wubx_dd ( id int(11)); Query OK, 0 rows affected (0.00 sec)
建立相应的触发程器
记录insert的操作：
delimiter // create trigger wubx_ii after insert on wubx for each row begin insert into wubx_ii set id=new.id,user_id=new.user_id,friend_id=new.friend_id,dir_id=new.dir_id,created=new.created; end//
记录update的操作：
create trigger wubx_uu after update on wubx for each row begin replace into wubx_uu set id=new.id,user_id=new.user_id,friend_id=new.friend_id,dir_id=new.dir_id,created=new.created; end//
记录删除的操作：
create trigger wubx_dd after delete on wubx for each row begin insert into wubx_dd values(old.id); end// delimiter ;
操作：
先备份原始表wubx里的数据：
进行：
insert into wubx values(”,1,10,1,1198464252); insert into wubx values(”,1,11,1,1198464252); insert into wubx values(”,1,2,1,1198464252); insert into wubx values(”,2,10,1,1198464252); insert into wubx values(”,2,12,1,1198464252); insert into wubx values(”,3,12,1,1198464252); update wubx set dir_id=5 where user_id=3; update wubx set dir_id=4 where user_id=3; delete from wubx where user_id=2 and friend_id=12;
现在要实现增量备份：
取出insert的操作：
mysql -e ” select concat(‘replace into wubx set id=',id,',user_id=',user_id,',friend_id=',friend_id,',dir_id=',dir_id,',created=',created,';') from wubx_ii;”>>backup_ii.sql
取出update的操作：
mysql -e ” select concat(‘update wubx set user_id=',user_id,',friend_id=',friend_id,',dir_id=',dir_id,',created=',created,' where id=',id,';') from wubx_uu;”>>backup_uu.sql
取出delete的操作：
mysql -e “select concat(‘delete from wubx where id=',id,';') from wubx_dd”>>backup_dd.sql
这样利用这些逻辑的备份加是完毕备份恢复到当前恢复点就很容易了。这里不演示。
这个操作最好用一个程序完成，当取完罗辑备份后，做一个标记点去清楚备份完的数据，以保证，逻辑记录表里的数据量比较少是正确的。
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
How to use MySQL backup and restore in PHP?
Jun 03, 2024 pm 12:19 PM
Backing up and restoring a MySQL database in PHP can be achieved by following these steps: Back up the database: Use the mysqldump command to dump the database into a SQL file. Restore database: Use the mysql command to restore the database from SQL files.
How to optimize MySQL query performance in PHP?
Jun 03, 2024 pm 08:11 PM
MySQL query performance can be optimized by building indexes that reduce lookup time from linear complexity to logarithmic complexity. Use PreparedStatements to prevent SQL injection and improve query performance. Limit query results and reduce the amount of data processed by the server. Optimize join queries, including using appropriate join types, creating indexes, and considering using subqueries. Analyze queries to identify bottlenecks; use caching to reduce database load; optimize PHP code to minimize overhead.
In summer, you must try shooting a rainbow
Jul 21, 2024 pm 05:16 PM
After rain in summer, you can often see a beautiful and magical special weather scene - rainbow. This is also a rare scene that can be encountered in photography, and it is very photogenic. There are several conditions for a rainbow to appear: first, there are enough water droplets in the air, and second, the sun shines at a low angle. Therefore, it is easiest to see a rainbow in the afternoon after the rain has cleared up. However, the formation of a rainbow is greatly affected by weather, light and other conditions, so it generally only lasts for a short period of time, and the best viewing and shooting time is even shorter. So when you encounter a rainbow, how can you properly record it and photograph it with quality? 1. Look for rainbows. In addition to the conditions mentioned above, rainbows usually appear in the direction of sunlight, that is, if the sun shines from west to east, rainbows are more likely to appear in the east.
How to insert data into a MySQL table using PHP?
Jun 02, 2024 pm 02:26 PM
How to insert data into MySQL table? Connect to the database: Use mysqli to establish a connection to the database. Prepare the SQL query: Write an INSERT statement to specify the columns and values to be inserted. Execute query: Use the query() method to execute the insertion query. If successful, a confirmation message will be output.
How to create a MySQL table using PHP?
Jun 04, 2024 pm 01:57 PM
Creating a MySQL table using PHP requires the following steps: Connect to the database. Create the database if it does not exist. Select a database. Create table. Execute the query. Close the connection.
How to use MySQL stored procedures in PHP?
Jun 02, 2024 pm 02:13 PM
To use MySQL stored procedures in PHP: Use PDO or the MySQLi extension to connect to a MySQL database. Prepare the statement to call the stored procedure. Execute the stored procedure. Process the result set (if the stored procedure returns results). Close the database connection.
How to fix mysql_native_password not loaded errors on MySQL 8.4
Dec 09, 2024 am 11:42 AM
One of the major changes introduced in MySQL 8.4 (the latest LTS release as of 2024) is that the "MySQL Native Password" plugin is no longer enabled by default. Further, MySQL 9.0 removes this plugin completely. This change affects PHP and other app
How to retrieve the wrong chain of virtual currency? Tutorial on retrieving the wrong chain of virtual currency transfer
Jul 16, 2024 pm 09:02 PM
The expansion of the virtual market is inseparable from the circulation of virtual currency, and naturally it is also inseparable from the issue of virtual currency transfers. A common transfer error is the address copy error, and another error is the chain selection error. The transfer of virtual currency to the wrong chain is still a thorny problem, but due to the inexperience of transfer operations, novices often transfer the wrong chain. So how to recover the wrong chain of virtual currency? The wrong link can be retrieved through a third-party platform, but it may not be successful. Next, the editor will tell you in detail to help you better take care of your virtual assets. How to retrieve the wrong chain of virtual currency? The process of retrieving virtual currency transferred to the wrong chain may be complicated and challenging, but by confirming the transfer details, contacting the exchange or wallet provider, importing the private key to a compatible wallet, and using the cross-chain bridge tool
