java-persistence-api

Difference between FetchType LAZY and EAGER in Java Persistence API?

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I am a newbie to Java Persistence API and Hibernate. What is the difference between FetchType.LAZY and FetchType.EAGER in Java Persistence API? 17 s 17 Sometimes you have two entities and there’s a relationship between them. For example, you might have an entity called University and another entity called Student and a University might have … Read more

JPA EntityManager: Why use persist() over merge()?

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EntityManager.merge() can insert new objects and update existing ones. Why would one want to use persist() (which can only create new objects)? 15 s 15 Either way will add an entity to a PersistenceContext, the difference is in what you do with the entity afterwards. Persist takes an entity instance, adds it to the context … Read more