centos安装LAMP环境时访问本地MYSQL数据库错误

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近日在安装LAMP环境时访问本地MYSQL数据库错误
错误如下：

Warning: mysqli::mysqli(): (HY000/2002): Can't connect to local MySQL server
问题描述：
由于将安装mysql服务器文件位置修改在home目录下，造成本地访问问题。

在网上找了很久终于找到解决问题的方法：
1、先确保在本机上使用命令能登陆，如果也出现提示sock文件位置问题，那么需要修改mysql配置文件（/etc/my.cnf）
增加如下配置：
[mysql]

socket=/home/mysqldata/mysql.sock#这是我的sock文件的位置
2、php使用mysqli无法访问问题
解决方法：
找到PHP配置文件(/etc/php.ini)找到mysqli.default_socket这个值
修改为mysqli.default_socket =/home/mysqldata/mysql.sock#这是我的sock文件的位置

问题分析（这是我在网上找到的解决方案）：
On Unix, MySQL programs treat the host name localhost specially, in a way that is likely different from what you expect compared to other network-based programs. For connections to localhost, MySQL programs attempt to connect to the local server by using a Unix socket file. This occurs even if a --port or -P option is given to specify a port number. To ensure that the client makes a TCP/IP connection to the local server, use --host or -h to specify a host name value of 127.0.0.1, or the IP address or name of the local server. You can also specify the connection protocol explicitly, even for localhost, by using the --protocol=TCP option.

其实就是说UNIX系统需要将localhost 这个地址进行转换的文件
解决的方法其他有三个

There are a few ways to solve this problem.

• You can just use TCP/IP instead of the Unix socket. You would do this by using 127.0.0.1instead of localhost when you connect. The Unix socket might by faster and safer to use, though.
  
• You can change the socket in php.ini: open the MySQL configuration file my.cnf to find where MySQL creates the socket, and set PHP's mysqli.default_socket to that path. On my system it's /var/run/mysqld/mysqld.sock.
  
• Configure the socket directly in the PHP script when opening the connection. For example:
  $db = new MySQLi('localhost', 'kamil', '***', '', 0,                               '/var/run/mysqld/mysqld.sock')
  

1、修改连接文件中localhost 为127.0.0.1
2、查看my.cnf文件中sock文件的位子，并赋值到php.ini:文件中的mysqli.default_socket去

3、PHP语言直接多一个参数指向sock文件位置。