Problem relationship classes

[andersonf]

Takes a lot of help from friends to solve this problem.

I'm having some problems while implementing on one class two different types of relations to another class.

As an example imagine an Author having a list of written books and then one which is his prefered one.

From the Grails GORM reference page I was able to implement the correct Many-to-Many relationship as follow:

class Author {
    static hasMany = [books: Book]
}

class Book {
    static belongsTo = Author
    static hasMany = [authors : Author]
}

Which is buy the way working perftectly. The problem comes when I want to add the preferedBook relation to the Author class:

class Author {
    Book prefered //My prefered book
    static hasMany = [books: Book]
}

The problem that happens here is that it was created two new tables from many to many.

I need to be created to link table many to many.
author_books:
  author_id
  book_id

And I need to have on the table the author has prefered_book_id.

I appreciate this now.

Anderson

[bhushan154]

Hi Anderson,

Sorry if I don't understand your requirement correctly but isn't this kind of what you are trying to do

class Author {
    static hasMany = [books: Book, preferredBooks: Book]
}