From the Grails belongsTo documentation, what is the use of
class Book {
static belongsTo = Author
}
What is the impact of cascading operations on Book, when CRUD operations performed on Author?
EDIT:
Thanks for your responses, may be i didn't specify my question correctly. I would like to know the difference between
static belongsTo [author:Author]
vs
static belongsTo = Author
belongsTo
is helpful if you need a reference back to the owning object. In this case it is likely that an Author
has many Book
s. But maybe you're using a book object and want to mention that book instance's Author
. That is a good way to get it.
As far as CRUD goes, deleting or updating the book will not do anything to the Author
, but deleting the Author
will delete the Book
. If you don't add belongsTo
then there will be no cascading saves/updates/deletes, you will have to do it manually.
Example:
def a = new Author(name: 'J.K. Rawling')
a.addToBooks(new Book(title: 'Harry Potter 1'))
a.addToBooks(new Book(title: 'Harry Potter 2'))
a.save() // Saves author and book instances
a.delete() // Author and both books are deleted
Edit:
The OP updated their question, and I'm honestly not sure what the answer would be. Hopefully Burt Beckwith will show up soon! Good question, OP.