The Grails Framework 3.3.3

(Quick Reference) ## fetch ### Purpose Configures the fetching behavior of an association. ### Examples
    class Author {

        static hasMany = [books: Book]

        static mapping = {
            books fetch: 'join'
        }
    }
### Description Usage: `association_name(fetch:string)` Arguments: `fetchStrategy` - The fetching strategy to use. Either `join` or `select`. By default GORM assumes fetching of associations is done using a `SELECT` when the association is accessed. If you prefer that the association be fetched eagerly at the same time then you can override the behavior:
    class Author {

        static hasMany = [books: Book]

        static mapping = {
            books fetch: 'join'
        }
    }
Here the `books` association will be fetched using a join at the same time the author is retrieved, for example:
    def author = Author.get(1)
    // the books collection is pre-initialized - no risk of lazy loading exceptions
Note that excessive use of joins can be a performance bottleneck. See the section on Eager vs Lazing Fetching in the user guide. | Quick Reference (hide)