Questions tagged [jpa]
The Jakarta Persistence API (formerly Java Persistence API) (JPA) is a Java specification for accessing, persisting, and managing data between Java objects/classes and a relational database. JPA was defined as part of the EJB 3.0 specification as a replacement for the EJB 2 CMP Entity Beans specification. JPA is now considered the standard industry approach for Object to Relational Mapping (ORM) in the Java Industry.
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Validation Error: Value is not valid
I have a problem with a p:selectOneMenu, no matter what I do I cannot get JSF to call the setter on the JPA entity. JSF validation fails with this message:
form:location: Validation Error: Value is ...
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JSF Controller, Service and DAO
I'm trying to get used to how JSF works with regards to accessing data (coming from a spring background)
I'm creating a simple example that maintains a list of users, I have something like
<h:...
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JPA JoinColumn vs mappedBy
What is the difference between:
@Entity
public class Company {
@OneToMany(cascade = CascadeType.ALL , fetch = FetchType.LAZY)
@JoinColumn(name = "companyIdRef", referencedColumnName ...
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JPA EntityManager: Why use persist() over merge()?
EntityManager.merge() can insert new objects and update existing ones.
Why would one want to use persist() (which can only create new objects)?
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How can I make a JPA OneToOne relation lazy
In this application we are developing, we noticed that a view was particularly slow. I profiled the view and noticed that there was one query executed by hibernate which took 10 seconds even if there ...
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PersistentObjectException: detached entity passed to persist thrown by JPA and Hibernate
I have a JPA-persisted object model that contains a many-to-one relationship: an Account has many Transactions. A Transaction has one Account.
Here's a snippet of the code:
@Entity
public class ...
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No Persistence provider for EntityManager named
I have my persistence.xml with the same name using TopLink under the META-INF directory.
Then, I have my code calling it with:
EntityManagerFactory emfdb = Persistence.createEntityManagerFactory("...
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How to fix the Hibernate "object references an unsaved transient instance - save the transient instance before flushing" error
I receive following error when I save the object using Hibernate
object references an unsaved transient instance - save the transient instance before flushing
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Difference between FetchType LAZY and EAGER in Java Persistence API?
What is the difference between FetchType.LAZY and FetchType.EAGER in Java Persistence API?
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Hibernate throws MultipleBagFetchException - cannot simultaneously fetch multiple bags
Hibernate throws this exception during SessionFactory creation:
org.hibernate.loader.MultipleBagFetchException: cannot simultaneously fetch multiple bags
This is my test case:
Parent.java
@...
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How does spring.jpa.hibernate.ddl-auto property exactly work in Spring?
I was working on my Spring boot app project and noticed that, sometimes there is a connection time out error to my Database on another server(SQL Server).
This happens specially when I try to do some ...
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JPA : How to convert a native query result set to POJO class collection
I am using JPA in my project.
I came to a query in which I need to make join operation on five tables. So I created a native query which returns five fields.
Now I want to convert the result object ...
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Spring Data JPA - ZonedDateTime format for json serialization
I have a problem with the json serialization of ZonedDateTime. When converted to json it produces an enormous object and I don't want all that data to be transfered every time. So i tried to format it ...
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How to map a composite key with JPA and Hibernate?
In this code, how to generate a Java class for the composite key (how to composite key in hibernate):
create table Time (
levelStation int(15) not null,
src varchar(100) not null,
dst ...
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How to map an entity field whose name is a reserved word in JPA
@Column(name="open")
Using sqlserver dialect with hibernate.
[SchemaUpdate] Unsuccessful: create table auth_session (id numeric(19,0) identity not null, active tinyint null, creation_date datetime ...
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