hibernate报错：Column 'id' cannot be null

报错内容：

17:21:59,843  INFO org.hibernate.tool.hbm2ddl.SchemaExport:226 - Running hbm2ddl schema export
  17:21:59,859 DEBUG org.hibernate.tool.hbm2ddl.SchemaExport:242 - import file not found: /import.sql
  17:21:59,859  INFO org.hibernate.tool.hbm2ddl.SchemaExport:251 - exporting generated schema to database
  17:21:59,859 DEBUG org.hibernate.tool.hbm2ddl.SchemaExport:377 - drop table LongMao if exists
  17:21:59,859 DEBUG org.hibernate.tool.hbm2ddl.SchemaExport:362 - Unsuccessful: drop table LongMao if exists
  17:21:59,859 DEBUG org.hibernate.tool.hbm2ddl.SchemaExport:363 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘if exists‘ at line 1
  17:21:59,859 DEBUG org.hibernate.tool.hbm2ddl.SchemaExport:377 - create table LongMao (id integer generated by default as identity (start with 1), name varchar(255), primary key (id))
  17:21:59,859 ERROR org.hibernate.tool.hbm2ddl.SchemaExport:348 - Unsuccessful: create table LongMao (id integer generated by default as identity (start with 1), name varchar(255), primary key (id))
  17:21:59,859 ERROR org.hibernate.tool.hbm2ddl.SchemaExport:349 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘generated by default as identity (start with 1), name varchar(255), primary key ‘ at line 1
  17:21:59,859  INFO org.hibernate.tool.hbm2ddl.SchemaExport:268 - schema export complete
  Hibernate: insert into LongMao (id, name) values (null, ?)
17:21:59,953  WARN org.hibernate.util.JDBCExceptionReporter:100 - SQL Error: 1048, SQLState: 23000
  17:21:59,953 ERROR org.hibernate.util.JDBCExceptionReporter:101 - Column ‘id‘ cannot be null

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修改为：

 <!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>

注意：MySQL是这样拼的，第二个字母小写

建议直接去文档复制，不要再自己动手敲了