You can sort objects using queries arguments such as those found in the list method:

def airports = Airport.list(sort:'name')

However, you can also declare the default sort order for a collection in the mapping:

class Airport {
    …
    static mapping = {
        sort "name"
    }
}

The above means that all collections of Airports will be sorted by default by the airport name. If you also want to change the sort order , use this syntax:

class Airport {
    …
    static mapping = {
        sort name:"desc"
    }
}

Finally, you can configure the sorting at the association level:

class Airport {
    …
    static hasMany = [flights:Flight]

static mapping = { flights sort:'number', order:'desc' } }

In this case, the flights collection will always be sorted in descending order of flight number.