1

我正在尝试使用休眠和使用简单的程序来实现继承

好吧，我声明了一类人具有四个属性-年龄，性别，姓名，id（这是自动生成的）

现在我有两个继承基类的类

第一个类是本地的，其中一个属性定义了 pincode，而另一个类是外部的，其中定义了 psotcode

以下是我的整个代码

person.java

package com;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Person {
    private String Name;
    private int age;
    private String sex;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private String id;

    public String getName() {
        return Name;
    }

    public void setName(String name) {
        Name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }
}

本机.java

package com;

import javax.persistence.Entity;

@Entity
public class Native extends Person {
    private int pincode;

    public int getPincode() {
        return pincode;
    }

    public void setPincode(int pincode) {
        this.pincode = pincode;
    }
}


foreign.java

package com;

import javax.persistence.Entity;

@Entity
public class Foreign extends Person {
    private String postcode;

    public String getPostcode() {
        return postcode;
    }

    public void setPostcode(String postcode) {
        this.postcode = postcode;
    }
}

主类.java

package com;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;

public class Classmain {
    public static void main(String args[])

    {
        Person person = new Person();
        person.setName("krish");
        person.setSex("M");
        person.setAge(23);

        Native native = new Native();
        native.setPincode(201545);
        native.setAge(23);
        native.setName("victor");
        native.setSex("M");

        Foreign foreign = new Foreign();
        foreign.setPostcode("sfadfas0");
        foreign.setName("michelle");
        foreign.setAge(31);
        foreign.setSex("F");


        SessionFactory sessionfactory = new AnnotationConfiguration()
                .configure().buildSessionFactory();
        Session session = sessionfactory.openSession();
        session.beginTransaction();
        session.save(person);
        session.save(foreign);
        session.save(native);
        session.getTransaction().commit();
        session.close();

    }
}

以下是我的 hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
          "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
          "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
    <session-factory>
        <!-- Database connection settings -->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost:3306/Inherit1</property>
        <property name="connection.username">root</property>
        <property name="connection.password">vvvvvvvv</property>
        <property name="hbm2ddl.auto">update</property>


        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size">1</property>

        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>


        <mapping class="com.Person" />
        <mapping class="com.Native" />
        <mapping class="com.Foreign" />

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

但是我收到以下错误

INFO: HHH000232: Schema update complete
Hibernate: insert into Person (Name, age, sex, DTYPE) values (?, ?, ?, 'Person')
Jun 7, 2013 7:12:30 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
WARN: SQL Error: 1146, SQLState: 42S02
Jun 7, 2013 7:12:30 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
ERROR: Table 'Inherit1.Person' doesn't exist
Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not execute statement
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:123)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:136)
    at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:96)
    at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:58)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2975)
    at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3487)
    at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:81)
    at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:377)
    at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:214)
    at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:194)
    at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:178)
    at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:321)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:286)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:192)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:125)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:206)
    at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:191)
    at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
    at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:764)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:756)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:752)
    at com.Classmain.main(Classmain.java:33)
Caused by: com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: Table 'Inherit1.Person' doesn't exist
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:936)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2985)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1631)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1723)
    at com.mysql.jdbc.Connection.execSQL(Connection.java:3283)
    at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1332)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1604)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1519)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1504)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:133)
    ... 22 more

可能是什么原因？

4

2 回答 2

0

尝试将 @Table(name="table_name") 注释添加到继承的实体。

于 2013-06-07T14:06:20.177 回答
0

好的，我发现了你的错误，但你应该在日志中看到以前的错误：

ERROR: HHH000389: Unsuccessful: create table Person (DTYPE varchar(31) not null, id varchar(255) not null auto_increment, Name varchar(255), age integer not null, sex varchar(255), pincode integer, postcode varchar(255), primary key (id))
07-jun-2013 17:17:35 org.hibernate.tool.hbm2ddl.SchemaExport perform
ERROR: Incorrect column specifier for column 'id'

如果您查看 id 的定义，您会尝试在类中声明一个带有 String 变量的自增字段Person。用 int 改变它，它会完美地工作。

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int id;

创建了一个名为 Person 的唯一表，并正确插入了数据。

于 2013-06-07T14:07:25.257 回答