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 the association is fetched eagerly at the same time as object then you can override the fetch behavior:class Author {
static hasMany = [books:Book]
static mapping = {
books fetch:'join'
}
}
Here the books
association will be fetching using a join at the same time a particular author is looked up such as:def author = Author.get(1)
Note that excessive use joins can be a performance bottleneck. See the section on Eager vs Lazing Fetching in the user guide.