目前使用的hibernate5.2.9版本,配置的mysql方言为:
<property name="hibernate.dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>
使用的表更新策略为:
<property name="hibernate.hbm2ddl.auto">create</property>
可是每次执行都出现了以下错误:
INFO: HHH000423: Disabling contextual LOB creation as JDBC driver reported JDBC version [3] less than 4 Hibernate: drop table if exists NEWS 四月 15, 2017 1:38:33 下午 org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection INFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@180e6ac4] for (non-JTA) DDL execution was not in auto-commit mode; the Connection 'local transaction' will be committed and the Connection will be set into auto-commit mode. Hibernate: create table NEWS ( ID integer not null auto_increment, AUTHOR varchar(255), CONTENT varchar(255), CREATEDATE datetime, primary key (ID) ) type=InnoDB 四月 15, 2017 1:38:33 下午 org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection INFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@305f031] for (non-JTA) DDL execution was not in auto-commit mode; the Connection 'local transaction' will be committed and the Connection will be set into auto-commit mode. 四月 15, 2017 1:38:33 下午 org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleException WARN: GenerationTarget encountered exception accepting command : Error executing DDL via JDBC Statement org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL via JDBC Statement at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlString(SchemaCreatorImpl.java:440) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlStrings(SchemaCreatorImpl.java:424) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.createFromMetadata(SchemaCreatorImpl.java:315) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.performCreation(SchemaCreatorImpl.java:166) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:135) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:121) at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:155) at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72) at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:309) at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:445) at com.dx.hibernate5.test.HelloWord.main(HelloWord.java:40) Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: 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 'type=InnoDB' at line 7 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at com.mysql.jdbc.Util.handleNewInstance(Util.java:403) at com.mysql.jdbc.Util.getInstance(Util.java:378) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1031) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:957) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3361) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3295) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1852) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1975) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2470) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2399) at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:718) at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54) ... 11 more
根据提示很显然得知:这是MySQL的版本问题导致的问题。
实际上,在MySQL5.0以前,type=InnoDB是有效的SQL语句,但是自己用的是MySQL5.7版本,type=InnoDB不再有效了。
解决办法就是修改hibernate.cfg.xml中的dialect属性,将
<property name="dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>
修改为
<property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
再次运行,发现可以自动建表了。