冬眠＆amp; postgresql持久性ID不会自动持续存在（id必须是assi

Question

我收到以下错误：

javax.persistence.PersistenceException: org.hibernate.id.IdentifierGenerationException: ids for this class must be manually assigned before calling save(): com.xx.xx.xx.S3ObjectsEntity

我已经尝试过这个没有任何效果：

• ids for this class must be manually assigned before calling save():

• Hibernate: ids for this class must be manually assigned before calling save()

• ids for this class must be manually assigned before calling save() when entities have relation between their primary keys

• ids for this class must be manually assigned before calling save()

上述所有内容都不起作用，我收到相同的错误消息。

这是我的Entity.java：

@Entity
@Table(name = "s3objects", schema = "public", catalog = "CustomerReportBDD")
public class S3ObjectsEntity {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "s3objects_id",unique=true, nullable = false)
private Long s3Objects_Id;
@Basic
@Column(name = "etag", nullable = true, length = 100)
private String etag;
@Basic
@Column(name = "bucketname", nullable = true, length = 100)
private String bucketname;
@Basic
@Column(name = "objectkey", nullable = true, length = 100)
private String objectkey;
@Basic
@Column(name = "lastmodified", nullable = true, length = 100)
private String lastmodified;
@Basic
@Column(name = "storageclass", nullable = true, length = 100)
private String storageclass;
@Basic
@Column(name = "owner_id", nullable = true)
private Integer owner_id;

我用来创建表的sql脚本：

DROP TABLE IF EXISTS s3objects CASCADE;
CREATE TABLE s3objects (
s3objects_id   SERIAL,
etag          varchar(100),
bucketname    varchar(100),
objectkey     varchar(100),
lastmodified  varchar(100),
storageclass  varchar(100),
owner_id      varchar(100) ,
CONSTRAINT s3objectsKey PRIMARY KEY(s3objects_id)
);

所有者ID在基础中可以为空。

我工作完美，当我手动添加基础中的所有字段时（s3object_id＆amp; owner_id为null）

我试图在实体上做到这一点：

@GeneratedValue ( strategy=GenerationType.AUTO)

那：

@SequenceGenerator(name="s3ObjectSequence", sequenceName = "s3objects_s3objects_id_seq",allocationSize = 1)
@GeneratedValue ( strategy=GenerationType.SEQUENCE, generator = "s3ObjectSequence")

s3objects_s3objects_id_seq是在数据库中创建表后基础中存在的序列。

编辑1：

添加了选项

<properties>
  <property name="hibernate.jdbc.fetch_size" value="1000" />
  <property name="show_sql" value="true"/>
  <property name="hibernate.hbm2ddl.auto" value="create"/>
</properties>

在我的persist.xml

中

表是从实体创建的，但我总是得到相同的错误消息。

Answer 1

每个数据库驱动程序以不同的方式实现Id生成策略。你在用哪个司机？ JPA / hibernate版本？

尝试在开发环境中放置此hibernate选项“hibernate.hbm2ddl.auto = create”。它将自动创建您的表和序列。在脚本中复制生成的模式。

如果你输入@Id，你不需要在列上写“unique = true，nullable = false”。

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "s3objects_id")
private Long s3Objects_Id;