swift - 如何使用 Realm 更新/删除索引处的对象？

Question

今天我发现了Realm，但我对它并不熟悉。请帮忙。

我有两门课:

class EventDetail: Object {
dynamic var start_time : Int = 0
dynamic var end_time   : Int = 0
convenience init(start_time: Int, end_time: Int ) {
    self.init()
    self.start_time  = start_time
    self.end_time    = end_time
}
class Channel : Object {
  dynamic var id  : Int = 0
  convenience init ( id : Int) {
       self.id = id
  }
  let details = List<EventDetail>()
}

我像这样填充数据库:

let  realm = try! Realm()
var newChannel = Channel (id : id)
let detailEvent1 = EventDetail(start_time:10, end_time:  20)                              
let detailEvent2 = EventDetail(start_time:20,end_time: 30)
newChannel.details.append(detailEvent1)
newChannel.details.append(detailEvent2)

try! realm.write {
     realm.add(newChannel)
} 

问题是:如何删除/更新特定索引处的详细信息？

例如:从索引= 100的 channel 获取detailEvent2

Answer 1

您需要对要更改或删除的对象类型执行提取。

基本操作是

realm.objects(Channel.self)

要找出要更改或删除的对象，您可以使用简单的高阶函数来过滤结果，例如谓词:

let lateStarters = realm.objects(Channel.self).filter(NSPredicate(format: "start_time > 10", argumentArray nil))

并通过枚举结果数组来更改它们的属性:

try? realm.write({
    for channel in lateStarters {
        channel.start_time = 100
    }
})