使用Swift过滤Realm对象

Question

尝试使用以下方法过滤我的Realm数据库时,我总是遇到以下错误NSPredicate:

属性'text'不是'getType'类型对象中的链接

我想过滤我的Realm数据库,只显示其中包含特定文本的项目.这就是我尝试过的:

let realm = try! Realm()
let predicate = NSPredicate(format: "typez.text.filter = 'special'")
let filterThis = realm.objects(Publication).filter(predicate)
print(filterThis)

我的模型类的相关部分是:

class Publication: Object, Mappable {
    dynamic var id: Int = 0
    var typez = List<getType>()
    dynamic var url: String?
}

class getType: Object, Mappable {
    dynamic var text: String = ""
}

Answer 1

您提到模型类的相关部分如下所示:

class Publication: Object, Mappable {
    dynamic var id: Int = 0
    var typez = List<getType>()
    dynamic var url: String?
}

class getType: Object, Mappable {
    dynamic var text: String = ""
}

如果我理解正确,您希望找到列表中具有等于Publication的条目的实例.你可以表达为:typeztextspecial

let realm = try! Realm()
let result = realm.objects(Publication).filter("ANY typez.text = 'special'")
print(result)

Answer 2

我通常不直接使用 NSPredicate，而是在过滤器参数中执行内联谓词闭包。

let realm = try! Realm()
                     //Array of publications             
    let realmObjects = realm.objects(Publication)
    //any publication where .text property == special will be filtered. and filter out empty array
    let filterThis = realmObjects.filter({ $0.getType.filter({ $0.text == "special" } != [] ) })
    print(filterThis)