Top "Persistence" questions

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 …

java jpa persistence toplink

Hibernate: "Field 'id' doesn't have a default value"

I'm facing what I think is a simple problem with Hibernate, but can't solve it (Hibernate forums being unreachable certainly …

java hibernate jpa persistence

Setting a JPA timestamp column to be generated by the database?

In my SQL Server 2000 database, I have a timestamp (in function not in data type) column of type DATETIME named …

java jpa persistence annotations timestamp

Correct use of flush() in JPA/Hibernate

I was gathering information about the flush() method, but I'm not quite clear when to use it and how to …

java hibernate jpa transactions persistence

Confusion: @NotNull vs. @Column(nullable = false) with JPA and Hibernate

When they appear on a field/getter of an @Entity, what is the difference between them? (I persist the Entity …

java hibernate jpa persistence hibernate-annotations

When to use EntityManager.find() vs EntityManager.getReference() with JPA

I have come across a situation (which I think is weird but is possibly quite normal) where I use the …

java jakarta-ee jpa persistence

The import javax.persistence cannot be resolved

I'm currently working on a project that requires EntityManager EntityManagerFacotry and Persistence each from the javax.persistence package. It seems …

eclipse persistence

What are the differences between the different saving methods in Hibernate?

Hibernate has a handful of methods that, one way or another, takes your object and puts it into the database. …

java hibernate persistence

What is Persistence Context?

I am new to the Java world and JPA. I was studying JPA and came across many new terms like …

java jpa orm persistence

Java: JSON -> Protobuf & back conversion

I have an existing system, which is using protobuf-based communication protocol between GUI and server. Now I would like to …

java json serialization persistence protocol-buffers