我试图将一个示例项目导入到Eclipse中,并且在运行该应用程序时遇到以下给定的错误。
Caused by: org.hibernate.MappingException: org.hibernate.dialect.OracleDialect does not support identity key generation at org.hibernate.dialect.Dialect.getIdentityColumnString(Dialect.java:743) at org.hibernate.dialect.Dialect.getIdentityColumnString(Dialect.java:733) at org.hibernate.mapping.Table.sqlCreateString(Table.java:426) at org.hibernate.cfg.Configuration.generateSchemaCreationScript(Configuration.java:1028) at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:125) at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:492) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1744) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1782) at org.springframework.orm.hibernate4.LocalSessionFactoryBuilder.buildSessionFactory(LocalSessionFactoryBuilder.java:247) at org.springframework.orm.hibernate4.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:373) at org.springframework.orm.hibernate4.LocalSessionFactoryBean.afterPropertiesSet(LocalSessionFactoryBean.java:358) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1541) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1479) ... 32 more
按照此 SO链接,我已更改了
@GeneratedValue(strategy = GenerationType.IDENTITY)
至
@GeneratedValue(strategy = GenerationType.AUTO) 要么 @GeneratedValue(strategy = GenerationType.TABLE)
@GeneratedValue(strategy = GenerationType.AUTO)
@GeneratedValue(strategy = GenerationType.TABLE)
但是没有用。
这是代码:
User.java:
@Entity @Table(name = "users") @ManagedBean @ViewScoped public class User { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private int id; @Column(name = "username", nullable = false) private String username; @Column(name = "password", nullable = false) private String password; @Column(name = "role", nullable = false) private String role; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getRole() { return role; } public void setRole(String role) { this.role = role; } }
从applicationContext.xml:
<!-- Session Factory Declaration --> <bean id="SessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean"> <property name="dataSource" ref="DataSource" /> <property name="annotatedClasses"> <list> <value>com.crud.model.User</value> </list> </property> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">org.hibernate.dialect.OracleDialect</prop> <prop key="hibernate.show_sql">true</prop> <prop key="hibernate.hbm2ddl.auto">create</prop> </props> </property> </bean>
您可以使用告诉Hibernate使用序列来生成您的ID
@Id @Column(name = "ID") @GeneratedValue(strategy=GenerationType.SEQUENCE, generator = "id_Sequence") @SequenceGenerator(name = "id_Sequence", sequenceName = "ID_SEQ") private int id;
这个配置基本上告诉Hibernate使用一个名为ID_SEQ的数据库序列来生成该对象的ID。如果需要其他唯一ID,则可以在其他对象上指定其他序列;如果要在整个系统中使用全局唯一ID,则可以使用相同的序列。
唯一的缺点是不能执行批量插入(没有其他配置),因为Hibernate每次都需要从数据库中获取下一个序列值,如果要使用MySQL数据库,则不能使用此配置。 ,因为它们不支持序列。
如果没有任何意义,请通知我,我将作进一步解释。