(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 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.