创建简单的休眠应用程序时出现"表不存在"错误

Question

我在hibernate中有一个名为App.java的类，我在其中使用另一个ObjectAlien.java(一个pojo对象(将对象插入DB。我有一个配置文件，在其中我做了与数据库相关的配置。但当我运行App.java类时，我遇到了一个异常，比如Tabledosenot exist。请告诉我哪里出了问题。我正在提供我使用过的文件。

App.java

package com.telsuko.DemoHib;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
/**
* Hello world!
*
*/
public class App 
{
public static void main( String[] args )
{
Alien alien=new Alien();
alien.setAid(101);
alien.setAname("swathi");
alien.setColor("white");
/* addAnnotatedClass(Alien.class)- this we need to use, to specify that which class we are working with*/
Configuration cf=new Configuration().configure().addAnnotatedClass(Alien.class);
SessionFactory sf=cf.buildSessionFactory();
Session s=sf.openSession();
//we need to start transaction to perform any DB related operations in Hibernet
Transaction tx= s.beginTransaction();
s.save(alien);
tx.commit();
}
}

Alien.java

package com.telsuko.DemoHib;
import javax.persistence.Entity;
import javax.persistence.Id;
@Entity
public class Alien {
@Id
private int aid;
private String aname;
private String color;

public int getAid() {
return aid;
}
public void setAid(int aid) {
this.aid = aid;
}
public String getAname() {
return aname;
}
public void setAname(String aname) {
this.aname = aname;
}
public String getColor() {
return color;
}
public void setColor(String color) {
this.color = color;
}




}

hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"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.password">mysqlrootpwd</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/swathidb</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="hbm2ddl.auto">update</property>
</session-factory>
</hibernate-configuration>

异常堆栈跟踪。

Apr 23, 2021 12:20:37 AM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate ORM core version 5.4.30.Final
Apr 23, 2021 12:20:38 AM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.1.2.Final}
Apr 23, 2021 12:20:38 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
Apr 23, 2021 12:20:38 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/swathidb]
Apr 23, 2021 12:20:38 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: Connection properties: {password=****, user=root}
Apr 23, 2021 12:20:38 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit mode: false
Apr 23, 2021 12:20:38 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections <init>
INFO: HHH000115: Hibernate connection pool size: 20 (min=1)
Apr 23, 2021 12:20:38 AM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
Apr 23, 2021 12:20:39 AM org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection
INFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@65f651eb] 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.
Apr 23, 2021 12:20:39 AM org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleException
WARN: GenerationTarget encountered exception accepting command : Error executing DDL "create table Alien (aid integer not null, aname varchar(255), color varchar(255), primary key (aid)) type=MyISAM" via JDBC Statement
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL "create table Alien (aid integer not null, aname varchar(255), color varchar(255), primary key (aid)) type=MyISAM" via JDBC Statement
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applySqlString(AbstractSchemaMigrator.java:559)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applySqlStrings(AbstractSchemaMigrator.java:504)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.createTable(AbstractSchemaMigrator.java:277)
at org.hibernate.tool.schema.internal.GroupedSchemaMigratorImpl.performTablesMigration(GroupedSchemaMigratorImpl.java:71)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.performMigration(AbstractSchemaMigrator.java:207)
at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.doMigration(AbstractSchemaMigrator.java:114)
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:184)
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:73)
at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:318)
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:468)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:708)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:724)
at com.telsuko.DemoHib.App.main(App.java:24)
Caused by: java.sql.SQLSyntaxErrorException: 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 com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122)
at com.mysql.cj.jdbc.StatementImpl.executeInternal(StatementImpl.java:762)
at com.mysql.cj.jdbc.StatementImpl.execute(StatementImpl.java:646)
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54)
... 13 more
Apr 23, 2021 12:20:39 AM org.hibernate.engine.transaction.jta.platform.internal.JtaPlatformInitiator initiateService
INFO: HHH000490: Using JtaPlatform implementation: [org.hibernate.engine.transaction.jta.platform.internal.NoJtaPlatform]
Apr 23, 2021 12:20:39 AM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
WARN: SQL Error: 1146, SQLState: 42S02
Apr 23, 2021 12:20:39 AM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
ERROR: Table 'swathidb.alien' doesn't exist
Exception in thread "main" javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not execute statement
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:154)
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:181)
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:188)
at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1366)
at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:453)
at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3212)
at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2380)
at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:447)
at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:183)
at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$300(JdbcResourceLocalTransactionCoordinatorImpl.java:40)
at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:281)
at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:101)
at com.telsuko.DemoHib.App.main(App.java:29)
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:113)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:99)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:200)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3297)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3824)
at org.hibernate.action.internal.EntityInsertAction.execute(EntityInsertAction.java:107)
at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:604)
at org.hibernate.engine.spi.ActionQueue.lambda$executeActions$1(ActionQueue.java:478)
at java.base/java.util.LinkedHashMap.forEach(LinkedHashMap.java:684)
at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:475)
at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:345)
at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:40)
at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:93)
at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1362)
... 9 more
Caused by: java.sql.SQLSyntaxErrorException: Table 'swathidb.alien' doesn't exist
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:120)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:953)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1092)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdateInternal(ClientPreparedStatement.java:1040)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeLargeUpdate(ClientPreparedStatement.java:1348)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeUpdate(ClientPreparedStatement.java:1025)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:197)
... 20 more

Answer 1

这是一个方言问题，而不是org.hibernate.dialect.MySQLDialect使用org.hibernate.dialect.MySQL5Dialect。

此外，作为一般建议，我建议您始终查看堆栈跟踪，因为它提供了很多提示。