What are the four lifecycle states for an entity?
What are the four lifecycle states for an entity?
JPA’s 4 Lifecycle States. The lifecycle model consists of the 4 states transient, managed, removed, and detached.
What is the difference between Merge and persist?
Persist should be called only on new entities, while merge is meant to reattach detached entities. If you’re using the assigned generator, using merge instead of persist can cause a redundant SQL statement.
What is a soft delete?
What Is Soft Delete? Soft delete performs an update process to mark some data as deleted instead of physically deleting it from a table in the database. A common way to implement soft delete is to add a field that will indicate whether data has been deleted or not.
Why is EntityManager closed?
Why does the entity manager close? @JaySheth The entity manager could close after a DBAL exception, or if you’re doing an EntityManager->clear() before a flush. I’ve seen some people using DBAL exceptions to branch the execution flow, and then ending up with an EntityManager closed error.
When an entity object is persisted to the database using EntityManager its state changes to managed or persistent?
Persistent/Managed State : An entity object becomes Managed or Persistent when it is persisted to the database via an EntityManager’s persist() method, which must be invoked within an active transaction. Persistent state instances are always associated with persistence-context and transnational.
What is entity lifecycle?
The life cycle of entity objects consists of four states: New, Managed, Removed and Detached. When an entity object is initially created its state is New. In this state the object is not yet associated with an EntityManager. persistence.
What is a detached entity?
A detached entity is just an ordinary entity POJO whose identity value corresponds to a database row. The difference from a managed entity is that it’s not tracked anymore by any persistence context. An entity can become detached when the Session used to load it was closed, or when we call Session.
Why soft delete is better?
Soft deletion is a widely used pattern applied for business applications. It allows you to mark some records as deleted without actual erasure from the database. Effectively, you prevent a soft-deleted record from being selected, meanwhile all old records can still refer to it.
What is a hard delete?
hard deletion (countable and uncountable, plural hard deletions) (databases) An operation in which data is erased from the database (as opposed to a soft deletion).
