cxy1620541673的专栏

多表查询 SELECT * FROM a,b WHERE a.val = b.val; 连接查询 SELECT * FROM a LEFT JOIN b ON a.val = b.val; 重点：其实两种都是连接查询 多表查询即自然连接查询，如下 SELECT * FROM a join b WHERE a.val = b.val; 自然连接查询：默认使用

[root@localhost local]# rpm -Uhv http://www.percona.com/redir/downloads/percona-release/percona-release-0.0-1.x86_64.rpm [root@localhost local]# yum list|grep percona [root@localhost cxy]# yum insta

mysql\apache\php

主从服务器的作用： 1. 实现读写分离 2. 作为备份数据库，防止主库死机 主机：192.168.1.100 从机：192.168.1.101 配置步骤： （1）配置权限，为从机设置权限           mysql>GRANT REPLICATION SLAVE ON *.* TO ‘backup’@’192.168.1.101‘ IDENTIFIED BY ‘1

yum groupinstall "Development tools" yum install libxml2-devel gd-devel libmcrypt-devel libcurl-devel openssl-devel wget http://us3.php.net/get/php-5.5.5.tar.gz/from/cn2.php.net/mirror tar -xvf

centos7,mysql,nginx,php7