(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.
