//注册别名
    registerDialectAlias("hsqldb", HsqldbDialect.class);
    registerDialectAlias("h2", HsqldbDialect.class);
    registerDialectAlias("phoenix", HsqldbDialect.class);
    registerDialectAlias("postgresql", PostgreSqlDialect.class);
    registerDialectAlias("mysql", MySqlDialect.class); 
    registerDialectAlias("mariadb", MySqlDialect.class); 
    registerDialectAlias("sqlite", MySqlDialect.class);
    registerDialectAlias("herddb", HerdDBDialect.class);
    registerDialectAlias("oracle", OracleDialect.class); 
    registerDialectAlias("oracle9i", Oracle9iDialect.class); 
    registerDialectAlias("db2", Db2Dialect.class); 
    registerDialectAlias("informix", InformixDialect.class); 
    //解决 informix-sqli #129,仍然保留上面的 
    registerDialectAlias("informix-sqli", InformixDialect.class);
    registerDialectAlias("sqlserver", SqlServerDialect.class); 
    registerDialectAlias("sqlserver2012", SqlServer2012Dialect.class);
    registerDialectAlias("derby", SqlServer2012Dialect.class); 
    //达梦数据库,
http://github.com/mybatis-book/book/issues/43     registerDialectAlias("dm", OracleDialect.class); 
    //阿里云PPAS数据库,
http://github.com/pagehelper/Mybatis-PageHelper/issues/281     registerDialectAlias("edb", OracleDialect.class); 
    //神通数据库 
    registerDialectAlias("oscar", OscarDialect.class); 
    registerDialectAlias("clickhouse", MySqlDialect.class); 
    //瀚高数据库 
    registerDialectAlias("highgo", HsqldbDialect.class); 
    //虚谷数据库 
    registerDialectAlias("xugu", HsqldbDialect.class);