Grails domain class: unique constraint for multiple columns

Question

Suppose a simple Grails domain class:

class Account {
    String countryId;

    String userName;

    String password;

    static constraints = {
        .         


        

Answer 1

userName(unique: ['countryId'])

You can include as many other properties in the array that make up the other properties that must be considered in the "unique" constraint on the username.

So, for example if you wanted to make userName unique within a countryId and provinceId it would look like this:

userName(unique: ['countryId', 'provinceId']