Question

我现在面对这个错误很长一段时间了。我已经设法通过在HibernateUtil类中映射实体来找到解决方法。但是，我想使用hibernate.cfg.xml实现这一点。

我收到错误：

Exception in thread "main" javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not execute statement
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:147)
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:155)
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:162)
at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1441)
at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:491)
at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3201)
at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2411)
at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:467)
at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:146)
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:220)
at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:68)
at Main.main(Main.java:14)

Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'mydatabase.personentity' doesn't exist
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:422)
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:943)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3973)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3909)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2527)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2680)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2490)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1858)
at com.mysql.jdbc.PreparedStatement.executeUpdateInternal(PreparedStatement.java:2079)
at com.mysql.jdbc.PreparedStatement.executeUpdateInternal(PreparedStatement.java:2013)
at com.mysql.jdbc.PreparedStatement.executeLargeUpdate(PreparedStatement.java:5104)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1998)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:205)
... 18 more

Hibernate配置：

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration SYSTEM
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/mydatabase</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">password</property>
<property name="connection.pool_size">1</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="show_sql">true</property>
<property name="hbm2ddl.auto">update</property>
<!-- List of mapped classes -->
<mapping class="PersonEntity"/>

</session-factory>
</hibernate-configuration>

实体：

@Entity
public class PersonEntity
{
private int id;
private String name;

@Id
@Column(name = "ID")
public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}
@Column(name = "Name")
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
}

Hibernate Util：

public class HibernateUtil
{
private static final SessionFactory sessionFactory = buildSessionFactory();

private static SessionFactory buildSessionFactory() {
try {
    Configuration configuration = new Configuration();
    configuration.configure();        

    StandardServiceRegistry standardRegistry = new 
    StandardServiceRegistryBuilder()
            .configure()
            .build();

    return configuration.buildSessionFactory(standardRegistry);
}
catch(Exception e) {
    throw new ExceptionInInitializerError(e);
}
}

public static Session getSession()
{
return sessionFactory.openSession();
}

public static void close()
{
sessionFactory.close();
}
}

用于保存一些硬编码值的主类：

public class Main {
public static void main(String[] args) {
    PersonEntity personEntity = new PersonEntity();

    personEntity.setId(1);
    personEntity.setName("Cris");

    Session session = HibernateUtil.getSession();

    session.beginTransaction();
    session.save(personEntity);
    session.getTransaction().commit();

}

}

如果有人可以提供帮助，我将不胜感激，我认为这个问题存在于hibernate.cfg.xml中，但这只是我的猜测。提前致谢

Answer 1

如果数据库中存在表格，例如命名person，那么您应该使用@Table注释该实体：

@Entity
@Table(name = "person")
public class PersonEntity

如果您希望hibernate为您创建表格，则应首先将hbm2ddl.auto更改为create，然后将其更改回更新表已创建。

<property name="hbm2ddl.auto">create</property>

顺便说一句，hibernate.cfg.xml中的映射类应该是完整的包名。

Answer 2

尝试将<property name="hbm2ddl.auto">更改为<property name="hibernate.hbm2ddl.auto">（文档说明）

您也应该更改您的Sql Dialect。对于MySQL 5.x，如果使用org.hibernate.dialect.MySQL5InnoDBDialect表，则应使用InnoDB;如果不使用org.hibernate.dialect.MySQL5Dialect，则应使用{{1}}。

请参阅Session Configuration document。

Java / Hibernate表不存在错误

2 个答案: