Question

所以我正在尝试创建一个名为Author的类和一个名为Book的类。每个Book都与Author相关联。所以我有下面的表格模式：

CREATE TABLE author (
author_id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
name VARCHAR(30),
email VARCHAR(50),

PRIMARY KEY(author_id)
);

和

CREATE TABLE book (
book_id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
title VARCHAR(30),
description VARCHAR(50),
publish_date DATE,
author_id BIGINT UNSIGNED NOT NULL,

PRIMARY KEY(book_id),
FOREIGN KEY(author_id) REFERENCES author(author_id)
);

以下是相关的类：

@Entity
@Table(name="Author")
public class Author {

    @Id
    @GeneratedValue
    @Column(name="AUTHOR_ID")
    private long id;

    @Column(name="NAME")
    private String name;

    @Column(name="EMAIL")
    private String email;

    @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    private Set<Book> books;

    //Getters and setters below...

和

@Entity
@Table(name="Book")
public class Book {

    @Id
    @GeneratedValue
    @Column(name="BOOK_ID")
    private long id;

    @Column(name="TITLE")
    private String title;

    @Column(name="DESCRIPTION")
    private String description;

    @Column(name="PUBLISH_DATE")
    private Date publishDate;

    @ManyToOne
    @JoinColumn(name="AUTHOR_ID")
    private Author author;

    //Getters and setters below...

每当我尝试创建SessionFactory并保存/更新/删除数据时，我似乎必须有一个名为Author_Book的表。如果我让Hibernate创建表模式，它会自动创建它们。但是，如果我关闭了创建，它会说它找不到表Author_Book但我不想要那个表，因为它似乎没必要。此外，如果它创建Author_Book我无法删除作者或书中的任何内容，因为它表示表Author_Book中存在外键关联。

如何阻止Hibernate生成这些table1_table2模式。如果无法阻止它，或者由于某些原因该表很重要，如何在没有Hibernate的情况下删除/更新信息，说明Author_Book表中存在外键关系？

编辑：当我尝试transaction.commit()时出现错误。我得到以下堆栈跟踪：

Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not execute statement
    at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:80)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:126)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:112)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:190)
    at org.hibernate.engine.jdbc.batch.internal.NonBatchingBatch.addToBatch(NonBatchingBatch.java:62)
    at org.hibernate.persister.collection.AbstractCollectionPersister.recreate(AbstractCollectionPersister.java:1311)
    at org.hibernate.action.internal.CollectionRecreateAction.execute(CollectionRecreateAction.java:67)
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:453)
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:345)
    at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:350)
    at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:56)
    at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1218)
    at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:421)
    at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.beforeTransactionCommit(JdbcTransaction.java:101)
    at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.commit(AbstractTransactionImpl.java:177)
    at main.Test.main(Test.java:46)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'author1234.author_book' doesn't exist
    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:406)
    at com.mysql.jdbc.Util.getInstance(Util.java:381)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1030)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3558)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3490)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1959)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2109)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2643)
    at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2077)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2362)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2280)
    at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2265)
    at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:187)

我是否必须让Hibernate创建table1_table2模式或者是否可以禁用它？

0 个答案: