swift - 在 Realm Swift 中查询一对多关系中的项目

Question

如何根据以下代码查询列表中的所有项目？

我想要的是能够说，给我所有属于 List 1 等的项目。

购物 list 模型

import Foundation
import RealmSwift

class ShoppingList: Object{
    dynamic var listName = ""
    var itemList = List<Item>()
}

项目模型

import Foundation
import RealmSwift

class Item:Object {
    dynamic var productName: String = ""
}

所有 ShoppingLists 的输出(realm.objects(ShoppingList.self))

Lists: Results<ShoppingList> (
    [0] ShoppingList {
        listName = List 1;
        itemList = RLMArray <0x6180000feb80> (
            [0] Item {
                productName = Jitomates;
            },
            [1] Item {
                productName = Grapes;
            },
            [2] Item {
                productName = Oranges;
            }
        );
    },
    [1] ShoppingList {
        listName = List 2;
        itemList = RLMArray <0x6180000fec80> (
            [0] Item {
                productName = Tomatoes;
            },
            [1] Item {
                productName = Grapes;
            },
            [2] Item {
                productName = Oranges;
            },
            [3] Item {
                productName = Green Peppers;
            },
            [4] Item {
                productName = Apples;
            }
        );
    }
)

编辑:

下面的查询与我正在寻找的很接近，除了它输出一个 Results 并且我只需要一个 List 和 List 2< 中的所有项目/p>

let itemsFromList2 = realm.objects(ShoppingList.self).filter("listName = 'List 2' ")

Items: Results<ShoppingList> (
    [0] ShoppingList {
        listName = List 2;
        itemList = RLMArray <0x6000000e3500> (
            [0] Item {
                productName = Tomatoes;
            },
            [1] Item {
                productName = Grapes;
            },
            [2] Item {
                productName = Oranges;
            },
            [3] Item {
                productName = Green Pappers;
            },
            [4] Item {
                productName = Apples;
            }
        );
    }
)

Answer 1

您从 Realm 获取Results，然后从Results 获取 Realm 对象。希望下面的代码对您有所帮助。

let itemsFromList2 = realm.objects(ShoppingList.self).filter("listName = 'List 2'")
// Results acts like an Array
let shoppingList2 = itemsFromList2.first!
// itemList is what you need I think
let itemList = shoppingList2.itemList