# updateable

## Purpose

Determines whether a property's database column is updated when persistent instances are updated.

## Examples

    class Book {
        String title
        static belongsTo = [author: Author]
        …
        static mapping = {
            author insertable: false
            author updateable: false
        }
    }

## Description

Usage: `association_name(updateable: boolean)`

Useful in general where you don't want to update a value (or include the column in the generated SQL) during a `save()`.

In particular this is useful for one-to-many relationships. For example when you store the foreign key in the 'child' table, it's often efficient to save the child using only the foreign key of the parent. You do this by setting the parent object (and the parent foreign key) in the 'child' entity. Setting the attributes insertable:false and updateable:false for the 'belongsTo' parent object allows you to insert and update using only the foreign key.

    static mapping = {
        author updateable: false
    }