I have the following entity and their mapping
#Entity
#Table(name = "test")
public class Test implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequenceGenerator")
#SequenceGenerator(name = "sequenceGenerator", initialValue = 20000)
I want id value begins in 20000 but it doesn't work in postgresql. When the application starts I receive this exception
Caused by: org.hibernate.HibernateException: Multiple references to
database sequence [sequence_generator] were encountered attempting to
set conflicting values for 'initial value'. Fou nd [20000] and [1]
Do I need a extra configuration to it works?
PS: It is a new database without any previous configuration
You could try #TableGenerator annotation. Initial values can be set and seed other values.
You can find example and documentation here:
Set Initial Value Of Table Generator
Related
My application is using JPA for persisting data to Database.
The application has to generate Custom(encoded) sequence for performance reasons.
By default JPA seems to generate Ids for an entity using some sequence.
How to override default sequence generator with customer sequence generator in Java ? I want to have sequence generator in Java as I have a separate logic for that.
This is how you go with the custom sequence:
#Id
#SequenceGenerator(name = "pet_seq",
sequenceName = "pet_sequence",
initialValue = 1, allocationSize = 20)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "pet_seq")
#Column(name = "id", nullable = false)
private Long id;
In this case it will use pet_sequence instead of the default one. Also you can read this article for a better understanding of this subject.
I have adudited table with #Lob field. Without #Audited saving object by Spring CrudRepository works ok, but when i want audit turn on i get error: PSQLException: ERROR: column "content" is of type oid but expression is of type bytea. How to resolve this ? Content column in PostgreSQL database is oid type (for both tables). On Hibernate 5.x the same configuration works, but not o Hibernate 6.x.
#Entity
#Audited
#Table(name = "up_test")
#Getter #Setter
public class UploadTestEntity extends BaseEntity {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "up_test_seq")
#TableGenerator(table = "id_generator", name = "up_test_seq", initialValue = 1, allocationSize = 1)
private Integer id;
#Lob
private byte[] content;
}
Just remove the #Lob annotation.
The Postgres JDBC driver does not support handling the bytea type via the JDBC LOB APIs setBlob()/getBlob(). I don't know why, and it seems like something that should be supported.
But on the other hand, you don't need it here. The most natural way to handle a field of type byte[] mapping to bytea is to use setBytes()/getBytes(), which is the job of Hibernate's VarbinaryJdbcType.
I don't know where people got the idea that they needed to use #Lob for this instead of just going with the default mapping for byte[].
i have prob with mapping sequence auto increment
#GeneratedValue(strategy=GenerationType.SEQUENCE)
i'm using on sql developer it work but when i try on netbeans i get the message
Caused by: java.lang.NullPointerException
Create a sequence named SOME_SEQ in your db for this particular table. And use the annotations above your id field. allocationSize=1 means increment the value by 1. And some_seq_gen_name is for unique labeling.
#Id
#Column(name = "id")
#GeneratedValue(generator="some_seq_gen_name")
#SequenceGenerator(name="some_seq_gen_name", sequenceName="SOME_SEQ", allocationSize=1)
private Long id;
UPDATE: Based on your comment, for commit try this one:
EntityTransaction et = em.getTransaction();
et.begin();
// write persist code here
et.commit();
I am attempting to persist an entity with an attribute that I want to be populated from a DB sequence. I'm using Oracle, have created the sequence, verified the sequence works via sql, and yet my attribute isn't getting populated. Here's what I have:
#GeneratedValue(generator = "RFQ_LINE_IDS_SEQUENCE", strategy=GenerationType.SEQUENCE)
#SequenceGenerator(name="RFQ_LINE_IDS_SEQUENCE", sequenceName="RFQ_LINE_IDS_SEQUENCE", allocationSize=1000000000)
#Column(name = "external_line_item_id")
private String externalLineItemId;
All the examples I'm seen online show this annotation being used with #Id, but I have another attribute that I'm using for my id.
I've also tried the following to no avail:
#GeneratedValue(generator = "RFQ_LINE_IDS_SEQUENCE", strategy=GenerationType.SEQUENCE)
#GenericGenerator(name = "RFQ_LINE_IDS_SEQUENCE", strategy = "sequence",
parameters = {#Parameter(name = "sequence", value = "RFQ_LINE_IDS_SEQUENCE")})
#Column(name = "external_line_item_id")
private String externalLineItemId;
JPA only mandates support for #GeneratedValue on #Id fields. Some JPA implementations (such as DataNucleus JPA) support it but not all do.
I have created a proposal for JPA to support #GeneratedValue for non-id attributes. Please vote here for this to be included in 2.2
https://java.net/jira/browse/JPA_SPEC-113
I have an entity VM with a relationship to another entity BP. The relationship is eagerly fetched. First I load a VM. After loading the VM is detached, serialized and changed at the client side. Now I want to update the changed entity so I use the EntityManager.merge() method from JPA. Now I run into the following error from OpenJPA:
"Encountered new object in persistent field "Vm.bp" during attach. However, this field does not allow cascade attach. Set the cascade attribute for this field to CascadeType.MERGE or CascadeType.ALL (JPA annotations) or "merge" or "all" (JPA orm.xml). You cannot attach a reference to a new object without cascading."
Why do I have to add a Cascade.MERGE to a relationship to another entity that will never change? And why does JPA think that BP is a new object ("...cannot attach reference to a new object...")?
When using ManyToOne relationships do I always have to add Cascade.MERGE in order to update the entity or is this because of the EAGER fetch type?
Here's my entity:
#Entity
#Table(name = "VM")
public class Vm extends BaseEntity implements Serializable {
public static final long serialVersionUID = -8495541781540291902L;
#Id
#SequenceGenerator(name = "SeqVm", sequenceName = "SEQ_VM")
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SeqVm")
#Column(name = "ID")
private Long id;
// lots of other fields and relations
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "BP_ID")
private Bp bp;
// ...
}
I found the reason why this error message comes up: The #Version annotated database field of the related Bp entity was initialized with "0". Apparently OpenJPA (1.2.3) is not able to cope with entity versions of zero.
Setting the version to 1 solved my issue.