列出所有被安裝的rpm package

# rpm -qa | grep mariadb

mariadb-libs-5.5.50-1.el7_2.x86_64
mariadb-5.5.50-1.el7_2.x86_64
mariadb-server-5.5.50-1.el7_2.x86_64

解除安裝

# rpm -e mariadb-libs-5.5.50-1.el7_2.x86_64

此時報錯：

error: Failed dependencies:
    libmysqlclient.so.18()(64bit) is needed by (installed) postfix-2
 
:2.10.1-6.el7.x86_64
    libmysqlclient.so.18()(64bit) is needed by (installed) perl-DBD-MySQL-4.023-5.el7.x86_64
    libmysqlclient.so.18()(64bit) is needed by (installed) php-mysql-5.4.16-36.3.el7_2.x86_64
    libmysqlclient.so.18(libmysqlclient_18)(64bit) is needed by (installed) postfix-2:2.10.1-6.
 
el7.x86_64
    libmysqlclient.so.18(libmysqlclient_18)(64bit) is needed by (installed) perl-DBD-MySQL-4.023-5.el7.x86_64
    libmysqlclient.so.18(libmysqlclient_18)(64bit) is needed by (installed) php-mysql-5.4.16-36.3.el7_2.x86_64
    mariadb-libs(x86-64) = 1:5.5.50-1.el7_2 is needed by (installed) mariadb-1
 
:5.5.50-1.el7_2.x86_64
    mariadb-libs(x86-64) = 1:5.5.50-1.el7_2 is needed by (installed) mariadb-server-1:5.5.50-1.el7_2.x86_64

強制解除安裝，因為沒有–nodeps

# rpm -e --nodeps mariadb-libs-5.5.50-1.el7_2.x86_64

# rpm -e --nodeps mariadb-5.5.50-1.el7_2.x86_64

# rpm -e --nodeps mariadb-server-5.5.50-1.el7_2.x86_64 

然後可以安裝mysql了。