查看是否安装mysql的命令
rpm -qa | grep mysql
然后 逐个使用 rpm -e mysq-* 卸载
如果出现
error: Failed dependencies:
libmysqlclient.so.10 is needed by (installed) libdbi-dbd-mysql-0.6.5-10.RHEL4.1.i386
libmysqlclient.so.10 is needed by (installed) MySQL-python-1.0.0-1.RHEL4.1.i386
libmysqlclient.so.10 is needed by (installed) MyODBC-2.50.39-21.RHEL4.1.i386
libmysqlclient.so.10 is needed by (installed) qt-MySQL-3.3.3-9.3.i386
mysqlclient10 is needed by (installed) MySQL-python-1.0.0-1.RHEL4.1.i386
mysqlclient10 = 3.23.58-4.RHEL4.1 is needed by (installed) mysqlclient10-devel-3.23.58-4.RHEL4.1.i386
时，使用 --nodeps 参数，如：
rpm -e mysqlclient10-devel-3.23.58-4.RHEL4.1 --nodeps
rpm -e mysqlclient10-3.23.58-4.RHEL4.1 --nodeps
安装mysql 下载rpm包，按照下面的顺序安装
yum install mysql-community-common-5.7.15-1.el6.x86_64.rpm
yum install mysql-community-libs-5.7.15-1.el6.x86_64.rpm
yum install mysql-community-client-5.7.15-1.el6.x86_64.rpm
yum install mysql-community-server-5.7.15-1.el6.x86_64.rpm