Question

我认为应该很容易的事情真的很挣扎。

使用Swift 3.0，RealmSwift 2.4.2

我有两个模型，一个使用LinkingObjects与另一个模型呈反比关系。

class SetModel: Object {
    dynamic var name = ""
    let questions = List<QuestionModel>()
}

class QuestionModel: Object {
    dynamic var level = ""
    let sets = LinkingObjects(fromType: QuestionModel.self, property: "questions")
}

QuestionModels有多个SetModel。 SetModels有多个QuestionsModels。

SetModel可以有一个名称，如＆＃39; Food＆＃39;，＆＃39; Sport＆＃39;＆＃39; Travel＆＃39;等

在我的代码中的某个时刻，我需要找到一个QuestionModel的子集，它等同于许多不同的过滤选项，其中一个是Sets。即获得所有容易的问题＆＃39;在某些集合中。

我获得了许多套装，例如＆＃39; Food＆＃39; ＆安培; ＆＃39;旅游＆＃39;并且需要找到在他们的“集合”中设置的所有问题。属性。

fileprivate func applyFilters(objects: Results<QuestionModel>) -> Results<QuestionMode> {
    var res = objects

    // I have a session attribute that stores the values I need to filter on, 
    // one of which is a List<SetModels>
    if (session.sets.count > 0) {
        // These are the things I've tried, and the error messages :(

        for s in session.sets {
            // *** Terminating app due to uncaught exception 'Invalid predicate', 
            // reason: 'Key paths that include an array property must use 
            // aggregate operations'
            res = res.filter("sets.name == \(s.name!)")
        }
        for s in session.sets {
            // *** Terminating app due to uncaught exception 'Invalid predicate', 
            // reason: 'Predicate with ANY modifier must compare a KeyPath with 
            // RLMArray with a value'
            res = res.filter("ANY sets.name == \(s.name!)")
        }

        for s in session.sets {
            // *** Terminating app due to uncaught exception 'NSInvalidArgumentException', 
            // reason: 'Unable to parse the format string "ANY sets == SetModel
            res = res.filter("ANY sets == \(s)")
        }
        // *** Terminating app due to uncaught exception 'Invalid predicate', 
        // reason: 'Key paths that include an array property must use aggregate 
        // operations'
        res = res.filter("sets.name IN \({'Food', 'Travel'})")
    }

    // Filter on level
    res = res.filter("level == 'easy'")

    return res
}

编辑：这里是一个问题集。它显示我可以访问集合并且那里有数据

po self.questionModel.sets
LinkingObjects<SetModel> (
[0] SetModel {
    uuid = 5899cb786f6986.79052132;
    name = Action;
    questions = RLMArray <0x7f9a529a6910> (
        [0] QuestionModel {
            question = What can you climb?;
            responses = Tree;
        },
        [1] QuestionModel {
            question = How could you get into town?;
            responses = Bus;
        }
    );
},
[1] SetModel {
    uuid = 5899cbc2938b87.61048461;
    name = Travel;
    questions = RLMArray <0x7f9a52c05d60> (
        [0] QuestionModel {
            question = How could you get into town?;
            responses = Bus;
        }
    );
}
)

任何帮助非常感谢

Answer 1

好吧，我在一天之后就把它想出来了......

let predicate = NSPredicate(format:"SUBQUERY(sets, $s, $s.name IN %@).@count > 0", ['Demo', 'Food'] )
res = res.filter(predicate)

老实说，有时候我觉得自己像一个学徒魔术师随便说法术：）

过滤与Realm Swift的反向关系

1 个答案: