我试图将一个示例项目导入到 Eclipse 中,但在运行应用程序时遇到了以下给定的错误。
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
根据 this SO链接,我已经更改了
@GeneratedValue(strategy = GenerationType.IDENTITY)
到
@GeneratedValue(strategy = GenerationType.AUTO)
或 @GeneratedValue(strategy = GenerationType.TABLE)
但是没用。
代码如下:
用户.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;
}
}
来自 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>
最佳答案
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 的数据库序列来为这个对象生成 ID。如果您想要其他唯一 ID,您可以在其他对象上指定其他序列,或者如果您想要整个系统的全局唯一 ID,您可以使用相同的序列。
唯一的缺点是不能执行批量插入(没有一些进一步的配置)因为Hibernate每次都需要从数据库中获取下一个序列值,如果你想使用你不能使用这个配置MySQL 数据库,因为它们不支持序列。
如果有任何不明白的地方请告诉我,我会进一步解释。
关于java - org.hibernate.dialect.OracleDialect 不支持身份 key 生成,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/24009042/