https://www.jb51.net/article/118853.htm
如果之前源码安装过mysql5.6的话，卸载方法如下：
rm -rf /var/lib/mysql/
rm -rf /usr/local/mysql
rm -rf /etc/init.d/mysql
源码安装实践记录：
wget https://cdn.mysql.com/archives/mysql-5.6/mysql-5.6.27-linux-glibc2.5-x86_64.tar.gz
tar -zxf mysql-5.6.27-linux-glibc2.5-x86_64.tar.gz
mv mysql-5.6.27-linux-glibc2.5-x86_64 /usr/local/mysql
groupadd mysql
useradd -r -g mysql mysql
cd /usr/local/mysql
yum -y install perl* #客官如果执行下面这步报错，就执行这边，否则请跳过这个命令。
./scripts/mysql_install_db --user=mysql
chown -R root:root ./
cp support-files/mysql.server /etc/init.d/mysql