由于序列问题,我无法保留任何实体。我使用Glssfish 4,Postgres 9.3 + JPA + EJB3和Netbeans 8。 在摘要之下:
Finest: persist() operation called on: MyUser{id=null, email=a@e.it, password=test, firstname=test, lastname=test, company=Test}.
Finest: Execute query ValueReadQuery(sql="select nextval('mom_seq_id')")
Finest: Connection acquired from connection pool [read].
Finest: reconnecting to external connection pool
Fine: select nextval(mom_seq_id)
Finest: Connection released to connection pool [read].
Warning: Local Exception Stack:
Exception [EclipseLink-7027] (Eclipse Persistence Services - 2.5.0.v20130507-3faac2b): org.eclipse.persistence.exceptions.ValidationException
Exception Description: The sequence named [mom_seq_id] is setup incorrectly. Its increment does not match its pre-allocation size.
at org.eclipse.persistence.exceptions.ValidationException.sequenceSetupIncorrectly(ValidationException.java:1604)
at org.eclipse.persistence.sequencing.StandardSequence.createVector(StandardSequence.java:96)
...
Postgres上的序列:
CREATE SEQUENCE my_seq_id
INCREMENT 1
MINVALUE 1
MAXVALUE 9223372036854775807
START 27
CACHE 1;
ALTER TABLE my_seq_id
OWNER TO postgres;
COMMENT ON SEQUENCE my_seq_id
IS 'Sequence for autoincrement id on MyClass';
我的实体的摘录:
@Entity
@Table(name = "myuser")
@XmlRootElement
public class MyUser implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@SequenceGenerator(name="MYSEQ",
sequenceName="my_seq_id")
@GeneratedValue(strategy = GenerationType.SEQUENCE,
generator="MYSEQ")
@Basic(optional = false)
@Column(name = "id")
private Integer id;
任何人都可以解释什么是错的吗? 感谢
我解决了我的问题,但我不知道为什么!我看到allocationSize()的默认值是50:
package javax.persistence;
@Target(value = {ElementType.TYPE, ElementType.METHOD, ElementType.FIELD})
@Retention(value = RetentionPolicy.RUNTIME)
public @interface SequenceGenerator {
public String name();
public String sequenceName() default "";
public String catalog() default "";
public String schema() default "";
public int initialValue() default 1;
public int allocationSize() default 50;
}
我已将Postgres序列increment_by
的值从1更新为50,现在可以正常工作了!
答案 0 :(得分:4)
将INCREMENT的值从1改为50到我的Postgres序列解决了这个问题。正如@unwichtich所建议的那样,最好通过@SequenceGenerator注释指定allocationSize = 50属性。
答案 1 :(得分:3)
出于我理解的原因,JPA规范选择了50
作为序列生成器的默认增量。
PostgreSQL默认为1
。
如果两者不匹配,事情变得丑陋,因为JPA认为它可以使用别人也认为已分配的值。至少EclipseLink会检测到这一点; Hibernate只是继续尝试重新使用已经分配的密钥。
如果你的序列是:
CREATE SEQUENCE my_seq_id
INCREMENT 1
然后您的映射必须反映出:
@SequenceGenerator(name="MYSEQ",
sequenceName="my_seq_id", allocationSize=1)
我强烈建议明确说明增量,即使你将它保留为默认值50
并改为改变PostgreSQL序列。在稍后调试时,它会保存您和他人的理智。