rake aborted! Mysql:Error: query: not connected: CREATE TABLE `schema_migration

rake aborted! Mysql::Error: query: not connected: CREATE TABLE `schema_migration
rake aborted! Mysql::Error: query: not connected: CREATE TABLE `schema_migrations` (`version` varchar(255) NOT   NULL) ENGINE=InnoDB

       解决方式： 拷贝旧版的libmySQL.dll到ruby\bin下