DSL & Templates: Supporting Multiple UniqueConstraint for entities

[zhongweijun]

In some cases we need to define multiple UniqueConstraint for entities. For example, we have a User entity which have 4 attributes -- id, userName, mobileNumber, email. Apparently the field id is the identification for a user, and the userName, mobileNumber and email is not.

Here a requirement comes. Though the userName, mobileNumber and Email is not an entity identification, we still want the user could login the system by either his userName, mobileNumber or email. It means, the userName/mobileNumber/email could identify a user. In this case, we need a multiple UniqueConstraint for these 3 fields.

Entity User {
    Long id key;
    - @Username userName;  // basic type
    - @MobileNumber mobileNumber;  // basic type 
    - @Email email;               // basic type
    - @Password password;  // basic type
}

[tjuerge]

As a side note: The attribute "Long id key" is not valid here because this id attribute is added to every persistent domain object during model enrichment.

Regarding the id attribute Patrik stated in a forum post the following:

In Sculptor the id property has some very special meaning. It is always an autogenerated value. Used as primary key and foreign key relations.

[tjuerge]

As mentioned in a forum post this could be worked around via a gap class or by using the hint keyword and overriding DomainObjectAttributeAnnotationTmpl.columnAnnotations() via Sculptors extension mechnism.

[tjuerge]

How about using a single @UniqueConstraint with multiple columns?

Entity User {
    - @Username userName key;
    - @MobileNumber mobileNumber key; 
    - @Email email key;
    - @Password password;
}