The database server could be connected to (which means your username and password is okay) but the www_oamall_cn
database could not be selected.
www_oamall_cn
have permission to use the www_oamall_cn
database?username_www_oamall_cn
. Could that be the problem?If you do not know how to set up a database you should contact your host. If all else fails you may find help at the WordPress support forums.