用hibernate创建数据表的时候报错：Error executing DDL via JDBC Statement以及You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version和Table 'school.tb_role1' doesn't exists并且创建的表的后面 跟了一句type=myisam，而不是 engine=InnoDB
经过在网上搜索，我发现原因是：我在hibernate.cfg.xml中设置方言，写的是：
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>这种情况下默认使用的存储引擎是myisam，而myisam是不支持事务的
在MySQL5.5之后，应该使用engine=InnoDB，修改方法是设置方言为：
<property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>控制台显示：
Hibernate: create table tb_role1 (rid integer not null auto_increment, rolename varchar(255), primary key (rid)) engine=InnoDB
Hibernate: create table tb_user1 (id integer not null auto_increment, username varchar(255), password varchar(255), rid integer, primary key (id)) engine=InnoDB
Hibernate: alter table tb_user1 add constraint FKbckw392vin52fjokbogniayfj foreign key (rid) references tb_role1 (rid)
Hibernate: insert into tb_role1 (rolename) values (?)
Hibernate: insert into tb_user1 (username, password, rid) values (?, ?, ?)
Hibernate: insert into tb_user1 (username, password, rid) values (?, ?, ?)
Hibernate: update tb_user1 set rid=? where id=?
Hibernate: update tb_user1 set rid=? where id=?