hibernate.hbm2ddl.auto = create（不创建表）

Question

15 浏览2023年3月31日

匿名的 2023年4月1日

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我了解到hibernate.hbm2ddl.auto可以创建Schema并进行其他各种操作。但在我的情况下，它没有创建Schema。\n我在本地使用的是MYSQL，在我的本地主机上没有名为hibernate的Schema。\n我尝试了各种其他方法，但仍然得到相同的错误。\n

Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown database 'hibernate'
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

\n完整错误\n

 Aug 06, 2018 5:31:48 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.2.12.Final}
Aug 06, 2018 5:31:48 PM org.hibernate.cfg.Environment 
INFO: HHH000206: 未找到 hibernate.properties
Aug 06, 2018 5:31:49 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager 
INFO: HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
Aug 06, 2018 5:31:49 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: 使用Hibernate内置的连接池（非生产环境使用！）
Aug 06, 2018 5:31:49 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: 使用驱动程序 [com.mysql.jdbc.Driver] 的URL [jdbc:mysql://localhost:3306/hibernate]
Aug 06, 2018 5:31:49 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: 连接属性: {user=root, password=****}
Aug 06, 2018 5:31:49 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit模式: false
Aug 06, 2018 5:31:49 PM org.hibernate.engine.jdbc.connections.internal.PooledConnections 
INFO: HHH000115: Hibernate连接池大小: 20（最小=1）
Mon Aug 06 17:31:49 IST 2018 WARN: 不推荐在没有服务器身份验证的情况下建立SSL连接。根据MySQL 5.5.45+，5.6.26+和5.7.6+的要求，如果没有设置明确的选项，则必须默认建立SSL连接。为了符合现有不使用SSL的应用程序，verifyServerCertificate属性设置为'false'。您需要通过设置useSSL=false显式禁用SSL，或者设置useSSL=true并提供用于服务器证书验证的truststore。
Exception in thread "main" org.hibernate.service.spi.ServiceException: 无法创建所请求的服务[org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:271)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:233)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:242)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83)
    at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:418)
    at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
    at main.MainClass.main(MainClass.java:16)
Caused by: org.hibernate.exception.SQLGrammarException: 调用Driver#connect时出错
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:106)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator$1$1.convert(BasicConnectionCreator.java:101)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convertSqlException(BasicConnectionCreator.java:123)
    at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:41)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
    at org.hibernate.engine.jdbc.connections.internal.PooledConnections.addConnections(PooledConnections.java:123)
    at org.hibernate.engine.jdbc.connections.internal.PooledConnections.(PooledConnections.java:42)
    at org.hibernate.engine.jdbc.connections.internal.PooledConnections.(PooledConnections.java:20)
    at org.hibernate.engine.jdbc.connections.internal.PooledConnections$Builder.build(PooledConnections.java:161)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildPool(DriverManagerConnectionProviderImpl.java:109)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:72)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:242)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.buildJdbcConnectionAccess(JdbcEnvironmentInitiator.java:145)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:66)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:88)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:259)
    ... 14 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown database 'hibernate'
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
    at com.mysql.jdbc.Util.getInstance(Util.java:408)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:944)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3976)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3912)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:871)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1714)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1224)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2190)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2221)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2016)
    at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:776)
    at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:47)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
    at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:38)
    ... 29 more

\nhiberante.cfg.xml\n


    
        org.hibernate.dialect.MySQLDialect
        com.mysql.jdbc.Driver
        root
        root
        jdbc:mysql://localhost:3306/hibernate
        
        create
        false
        true

\nMODEL CLASS\n

package model;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
public class UserDetails {
    @Id
    private int userId;
    private String userName;
    public int getUserId() {
        return userId;
    }
    public void setUserId(int userId) {
        this.userId = userId;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    @Override
    public String toString() {
        return "UserDetails [userId=" + userId + ", userName=" + userName + "]";
    }
}

\nMAIN CLASS\n

package main;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import model.UserDetails;
public class MainClass {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        UserDetails obj=new UserDetails();
        obj.setUserId(1);
        obj.setUserName("ASHIHS");
        SessionFactory sessionfactory=new Configuration().configure().buildSessionFactory();
        Session session=sessionfactory.openSession();
        session.beginTransaction();
        session.save(obj);
        session.getTransaction().commit();
    }
}

\n在创建了Schema hibernate后更新错误日志\n

Aug 06, 2018 6:09:45 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.2.12.Final}
Aug 06, 2018 6:09:45 PM org.hibernate.cfg.Environment 
INFO: HHH000206: 未找到 hibernate.properties
Aug 06, 2018 6:09:45 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager 
INFO: HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
Aug 06, 2018 6:09:46 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: 使用Hibernate内置的连接池（非生产环境使用！）
Aug 06, 2018 6:09:46 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: 使用驱动程序 [com.mysql.jdbc.Driver] 的URL [jdbc:mysql://localhost:3306/hibernate]
Aug 06, 2018 6:09:46 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: 连接属性: {user=root, password=****}
Aug 06, 2018 6:09:46 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit模式: false
Aug 06, 2018 6:09:46 PM org.hibernate.engine.jdbc.connections.internal.PooledConnections 
INFO: HHH000115: Hibernate连接池大小: 20（最小=1）
Mon Aug 06 18:09:46 IST 2018 WARN: 不推荐在没有服务器身份验证的情况下建立SSL连接。根据MySQL 5.5.45+，5.6.26+和5.7.6+的要求，如果没有设置明确的选项，则必须默认建立SSL连接。为了符合现有不使用SSL的应用程序，verifyServerCertificate属性设置为'false'。您需要通过设置useSSL=false显式禁用SSL，或者设置useSSL=true并提供用于服务器证书验证的truststore。
Aug 06, 2018 6:09:47 PM org.hibernate.dialect.Dialect 
INFO: HHH000400: 使用方言: org.hibernate.dialect.MySQLDialect
Hibernate: drop table if exists UserDetails
Aug 06, 2018 6:09:47 PM org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection
INFO: HHH10001501: 从JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@488eb7f2]获取的连接用于（非JTA）DDL执行时不在自动提交模式中；连接'本地事务'将被提交，并将连接设置为自动提交模式。
Hibernate: create table UserDetails (userId varchar(255) not null, userName varchar(255), primary key (userId)) type=MyISAM
Aug 06, 2018 6:09:47 PM org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection
INFO: HHH10001501: 从JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@fb9c7aa]获取的连接用于（非JTA）DDL执行时不在自动提交模式中；连接'本地事务'将被提交，并将连接设置为自动提交模式。
Aug 06, 2018 6:09:48 PM org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleException
WARN: GenerationTarget遇到异常接受命令: 通过JDBC Statement执行DDL时出错
org.hibernate.tool.schema.spi.CommandAcceptanceException: 通过JDBC Statement执行DDL时出错
    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.(SessionFactoryImpl.java:313)
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:452)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:710)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
    at main.MainClass.main(MainClass.java:16)
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=MyISAM' at line 1
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
    at com.mysql.jdbc.Util.getInstance(Util.java:408)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:944)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3976)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3912)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2530)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2683)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2482)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2440)
    at com.mysql.jdbc.StatementImpl.executeInternal(StatementImpl.java:845)
    at com.mysql.jdbc.StatementImpl.execute(StatementImpl.java:745)
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54)
    ... 13 more
Aug 06, 2018 6:09:48 PM org.hibernate.tool.schema.internal.SchemaCreatorImpl applyImportSources
INFO: HHH000476: 执行导入脚本 'org.hibernate.tool.schema.internal.exec.ScriptSourceInputNonExistentImpl@40cb698e'
Hibernate: insert into UserDetails (userName, userId) values (?, ?)
Aug 06, 2018 6:09:48 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
WARN: SQL错误: 1146, SQL状态: 42S02
Aug 06, 2018 6:09:48 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
ERROR: 表 'hibernate.userdetails' 不存在
Aug 06, 2018 6:09:48 PM org.hibernate.engine.jdbc.batch.internal.AbstractBatchImpl release
INFO: HHH000010: 在释放批处理时仍然包含JDBC语句
Aug 06, 2018 6:09:48 PM org.hibernate.internal.ExceptionMapperStandardImpl mapManagedFlushFailure
ERROR: HHH000346: 托管刷新期间出错[org.hibernate.exception.SQLGrammarException: could not execute statement]
Exception in thread "main" javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not execute statement
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:149)
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:157)
    at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:164)
    at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1443)
    at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:493)
    at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3207)
    at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2413)
    at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:473)
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:156)
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$100(JdbcResourceLocalTransactionCoordinatorImpl.java:38)
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:231)
    at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:68)
    at main.MainClass.main(MainClass.java:20)
Caused by: org.hibernate.exception.SQLGrammarException: could not execute statement
    at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:63)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:97)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:178)
    at org.hibernate.engine.jdbc.batch.internal.NonBatchingBatch.addToBatch(NonBatchingBatch.java:45)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3013)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3513)
    at org.hibernate.action.internal.EntityInsertAction.execute(EntityInsertAction.java:89)
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:589)
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:463)
    at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:337)
    at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:39)
    at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1437)
    ... 9 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: 表 'hibernate.userdetails' 不存在
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
    at com.mysql.jdbc.Util.getInstance(Util.java:408)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:944)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3976)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3912)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:871)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1714)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1224)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2190)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2221)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2016)
    at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:776)
    at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:47)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
    at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:38)
    ... 29 more

0

2 答案

匿名的 · Answer 1 · 2023-05-06T00:34:17+00:00

在使用Hibernate时，有时候会遇到一个问题，即在配置文件中设置了hibernate.hbm2ddl.auto = create，但是却没有创建表。下面我们来分析一下出现这个问题的原因以及解决方法。

出现这个问题的原因可能有两个：配置文件中的属性设置有误；或者是数据库连接的问题。

首先，我们来检查配置文件中的属性设置。在配置文件中，我们需要将hibernate.hbm2ddl.auto属性设置为create，这样Hibernate会在启动时自动创建数据库表。但是有时候，我们可能会配置错误，导致这个属性没有生效。解决方法是检查配置文件中的属性设置，确保hibernate.hbm2ddl.auto的值为create。

其次，我们需要检查数据库连接是否正常。如果数据库连接有问题，Hibernate就无法创建表。解决方法是检查数据库连接的配置，确保数据库连接正确并且可以正常访问。

除了以上两个原因，还有可能是Hibernate版本不兼容导致的问题。在一些旧版本的Hibernate中，hibernate.hbm2ddl.auto属性可能不支持create值。解决方法是尝试将hibernate.orm_generation属性设置为create，这个属性可以在一些旧版本的Hibernate中使用。

总结一下，当配置文件中设置了hibernate.hbm2ddl.auto = create但是没有创建表时，我们需要检查配置文件中的属性设置是否正确，检查数据库连接是否正常，并且尝试使用hibernate.orm_generation属性来替代hibernate.hbm2ddl.auto属性。

希望以上的分析和解决方法对你有帮助！

匿名的 · Answer 2 · 2023-09-05T18:48:25+00:00

如果遇到以下问题，可以尝试以下解决方法。

问题描述：使用Hibernate时，设置hibernate.hbm2ddl.auto=create，但是并没有创建出相应的表。

问题原因：可能是因为使用的MySQL版本为5或以上，而没有正确设置数据库方言（dialect）导致。

解决方法：将数据库方言（dialect）设置为org.hibernate.dialect.MySQL55Dialect。

具体步骤如下：

1. 打开Hibernate配置文件。

2. 在配置文件中找到hibernate.dialect的属性设置。

3. 将属性值设置为org.hibernate.dialect.MySQL55Dialect。

4. 保存配置文件并重新运行程序。

这样的设置可以解决该问题。根据MySQL的版本不同，也可以尝试其他的方言设置，例如org.hibernate.dialect.MySQL5Dialect或org.hibernate.dialect.MySQL57Dialect。

希望以上解决方法可以帮助到有类似问题的用户。