ios - Realm 主键迁移 - Objective-C

Question

旧的 RLMObject 在下面，primaryKey 是 AttributeId。我想在下一次构建时将此键更改为@"Id"。

UserItemObject.m

@implementation UserItemObject {

}

+ ( NSString * )primaryKey; {
    return @"AttributeId";
}

@end

UserItemObject.h

@interface UserItemObject : RLMObject
   @property(nonatomic, copy) NSString *Id;
   @property(nonatomic, copy) NSString *AttributeId;
@end
RLM_ARRAY_TYPE(UserItemObject)

然后我给 AppDelegate 写了一些代码；

  [RLMRealm setSchemaVersion:1 forRealmAtPath:[RLMRealm defaultRealmPath] withMigrationBlock:^(RLMMigration *migration, NSUInteger oldSchemaVersion) {
      if ( oldSchemaVersion < 1 ) {
          [migration enumerateObjects: UserItemObject.className block:^(RLMObject *oldObject, RLMObject *newObject) {
                newObject[ @"primaryKeyProperty" ] = @"Id";
          }];
      }
  }];

这段代码给我一个错误；

*** Terminating app due to uncaught exception 'RLMException', reason: 'Invalid property name'

我该如何解决这个问题？非常感谢。

Answer 1

要更改主键属性，您需要更改 +[UserItemObject primaryKey] 的返回值。

然后，要真正进行迁移，您需要:

[RLMRealm setSchemaVersion:1 forRealmAtPath:[RLMRealm defaultRealmPath] withMigrationBlock:^(RLMMigration *migration, NSUInteger oldSchemaVersion) {
      if ( oldSchemaVersion < 1 ) {
          [migration enumerateObjects: UserItemObject.className block:^(RLMObject *oldObject, RLMObject *newObject) {
                newObject[ @"Id" ] = oldObject[@"AttributeId"];
          }];
      }
  }];