Grails, when to use merge () instead of save ()?

Question

Hello everyone, tell me when to use merge () instead of save () ?

I have some problems, for example, when I save a domain using the save () method , which works fine in some cases, but in some cases it throws an exception for me "org.hibernate.LazyInitializationException".

Is it possible to use the direct merge () method to save a domain instance instead of save () ?

Answer 1

You can see that the methods merge()and save()calling the method save()inside, the difference in their behavior, i.e. if you store an object in an HTTP session and later want to access it, but this object has lost its constant context, the merge () method merges the state of an individual object back into the current Hibernate session. But if you call the save () method on an individual object, you will encounter a sexual exception ( org.hibernate.LazyInitializationException), as you mentioned. For more information, documentation .