if not exists(select name from sys.objects where type_desc = 'DEFAULT_CONSTRAINT' and name = 'DF_UserRoamingSettings_ModifiedDate')
    alter table dbo.UserRoamingSettings add constraint DF_UserRoamingSettings_ModifiedDate default getutcdate() for ModifiedDate,
                                            constraint DF_UserRoamingSettings_CreationDate default getutcdate() for CreationDate;