Grails

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: None
• Fix Version/s: 1.1-beta2
• Component/s: Persistence
• Labels:

  None

The current enum support in GORM is quite good, but if you use an enum in high-volume domain class (i.e. a lot of rows) than the current approach on mapping the name() value becomes quite inefficient. Switching to the ordinal value can get you in troubles when performing refactorings/migrations. So I'd like to introduce an enhanced solution for the problem:

If the enum has an instance method "getId()" which has a return type that can be mapped as a hibernate basic type (string, int, double, ...) then grails automatically uses a custom usertype (IdentifierEnumType), which performs the mapping using that return value. The id-to-enum value mapping is performed using a bidirectional inmemory map, so it should be quite efficient.
(the feature can be turned of with a configuration option in Config.groovy)

Some example enums that would be mapped with that usertype:

(Groovy version - mapped to the short string value)
public enum Country {

AUSTRIA('at'),
UNITED_STATES('us'),
GERMANY('de');

final String id;

Country(String id) { this.id = id; }
}

(Java Version)
public enum Genre {

UNKONWN(-1),
SCIENCE_FICTION(0),
FANTASIY(1),
BIOGRAPHY(2),
NON_FICTION(3);

private final int idVal;

Genre(int id) { this.idVal = id; }

public int getId() { return idVal; }
}

• Assignee:

  Siegfried Puchbauer

  Reporter:

  Siegfried Puchbauer

• Created:

  26/Nov/08 5:57 AM

  Updated:

  18/May/11 8:41 AM

  Resolved:

  09/Dec/08 8:33 AM