我正在尝试创建一个简单的休眠应用程序。它给出了以下错误。如何解决该错误[重复]

Posted 2023-02-24

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【中文标题】我正在尝试创建一个简单的休眠应用程序。它给出了以下错误。如何解决该错误[重复]【英文标题】：i am trying to create a simple hibernate application.It gives following error.how to solve that error [duplicate] 【发布时间】：2017-11-12 18:44:30 【问题描述】：

MainClass.java

package com.binod.hibernate;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class MainClass 
   public static void main(String[] args) 

        StudentInfo studentInfo=new StudentInfo();
        studentInfo.setRollNo(1);
        studentInfo.setFirstName("Binod");
        studentInfo.setLastName("Pant");

        SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
        Session session = sessionFactory.openSession();
        session.beginTransaction();
        // this would save the Student_Info object into the database
        session.save(studentInfo);  
        session.getTransaction().commit();
        session.close();
        sessionFactory.close();

StudentInfo.java

package com.binod.hibernate;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="student")
public class StudentInfo 

    @Id
    private int rollNo;
    private String firstName,lastName;
    public int getRollNo() 
        return rollNo;
    
    public void setRollNo(int rollNo) 
        this.rollNo = rollNo;
    
    public String getFirstName() 
        return firstName;
    
    public void setFirstName(String firstName) 
        this.firstName = firstName;
    
    public String getLastName() 
        return lastName;
    
    public void setLastName(String lastName) 
        this.lastName = lastName;

hibernate.cfg.xml

<?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.dialect">
            org.hibernate.dialect.mysqlDialect
        </property>
        <property name="hibernate.connection.driver_class">
            com.mysql.jdbc.Driver
        </property>
        <!-- Assume test is the database name -->
        <property name="hibernate.connection.url">
            jdbc:mysql://localhost:3306/hibernatepractise
        </property>
        <property name="hibernate.connection.username">
            root
        </property>
        <property name="hibernate.connection.password">
            devbinod
        </property>
        <!-- show all executed sql -->
        <property name="show_sql">true</property>
        <!-- Drop Existing Table create new one -->
        <property name="hbm2ddl.auto">create</property>
        <!-- List of XML mapping files -->
        <mapping class="com.binod.hibernate.StudentInfo" />
    </session-factory>
</hibernate-configuration>

错误是

    INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
    Hibernate: drop table if exists student
    Jun 11, 2017 8:28:10 AM org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection
    INFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@134d26af] for (non-JTA) DDL execution was not in auto-commit mode; the Connection 'local transaction' will be committed and the Connection will be set into auto-commit mode.
    Hibernate: create table student (rollNo integer not null, firstName varchar(255), lastName varchar(255), primary key (rollNo)) type=MyISAM
    Jun 11, 2017 8:28:10 AM org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection
    INFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@331acdad] 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.
    Jun 11, 2017 8:28:10 AM 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:452)
        at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:710)
        at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
        at com.binod.hibernate.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(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: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:2486)
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2444)
        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

    Jun 11, 2017 8:28:10 AM org.hibernate.tool.schema.internal.SchemaCreatorImpl applyImportSources
    INFO: HHH000476: Executing import script 'org.hibernate.tool.schema.internal.exec.ScriptSourceInputNonExistentImpl@2e2ff723'
    Hibernate: insert into student (firstName, lastName, rollNo) values (?, ?, ?)
    Jun 11, 2017 8:28:10 AM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
    WARN: SQL Error: 1146, SQLState: 42S02
    Jun 11, 2017 8:28:10 AM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
    ERROR: Table 'hibernatepractise.student' doesn't exist
    Jun 11, 2017 8:28:10 AM org.hibernate.engine.jdbc.batch.internal.AbstractBatchImpl release
    INFO: HHH000010: On release of batch it still contained JDBC statements
    Jun 11, 2017 8:28:10 AM org.hibernate.internal.ExceptionMapperStandardImpl mapManagedFlushFailure
    ERROR: HHH000346: Error during managed flush [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: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 com.binod.hibernate.MainClass.main(MainClass.java:23)
    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:208)
        at org.hibernate.engine.jdbc.batch.internal.NonBatchingBatch.addToBatch(NonBatchingBatch.java:45)
        at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3003)
        at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3503)
        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:1435)
        ... 9 more
    Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'hibernatepractise.student' 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:423)
        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

我已经创建了一个学生表。Hibernate 删除表但不创建新表。如何解决这个问题。我找不到我的错误在哪里。

【问题讨论】：

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

看看这个，看来这是主要原因。 @AmitK 当我从 hibernate.cfg.xml 文件中删除 <property name="hbm2ddl.auto">create</property> 属性时它工作正常。而不是 ` create` 你应该使用 ` update` ，你不每次启动应用程序时都希望创建 Db。你能把你的 MySQL 方言改成org.hibernate.dialect.MySQL5Dialect 并检查一下吗？已经这样做了！ 【参考方案1】：

MySQL 方言更改自

`org.hibernate.dialect.MySQLDialect`

到

`org.hibernate.dialect.MySQL5Dialect`

应该可以解决您的问题。

发生这种情况的原因是 MySQL5Dialect 使用类型 MyISAM

问题是方言org.hibernate.dialect.MySQLDialect 是针对MySQL 4.x 或更早的。此方言生成的片段type=MyISAM 在 MySQL 4.0 中已弃用，并在 5.5 中删除。

有相当多的文档可用于单独使用 MySQL 的数据库引擎类型的方言。

【讨论】：

请注意，还有更新版本的方言可用是的，没错！【参考方案2】：

尽量不要使用这样的声明：

 private String firstName,lastName;

改用：

 private String firstName;
 private String lastName;

也可以查看link.

确保您使用正确版本的 Hibernate、JDBC 驱动程序和 MySQL 服务器

【讨论】：

@Binod Pant 如果您打开链接，我已在答案中添加并检查您的日志 - 您可以了解出了什么问题【参考方案3】：

尝试在 hibernate.cfg.xml 中进行更改：

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

到

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

我们不需要再次创建模式，它会破坏以前的数据。因此，更新 hibernate.hbm2ddl.auto 的值会更新架构。

【讨论】：

它只销毁以前的数据，但不创建新表。我想解释为什么在销毁新表后它不能创建新表。update 工作正常 Create 只会破坏数据，不会创建或删除表。 Schema只是代表逻辑视图的骨架结构。架构是使用 hbm2ddl.auto 中的创建变量创建的，而不是表。最初创建模式是休眠应用程序的必要条件。稍后，我们应该根据我们的要求使用创建或更新或验证。

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