ios - Realm Swift iOS - 无法设置主键
<p><p>我会尽量简短地解释我的场景,我已经阅读了 Realm GitHub Repo 上关于这个问题的一些评论:</p>
<blockquote>
<p>Terminating app due to uncaught exception 'RLMException', reason:
'Can't set primary key property 'id' to existing value 'xxxxxxx'.</p>
</blockquote>
<p>这是我的问题:</p>
<p>我有两个类。</p>
<p><strong>约会模型类</strong></p>
<pre><code>import Foundation
import RealmSwift
class Appointment: Object {
dynamic var id = 0
dynamic var user_id: String?
dynamic var profile_id: String?
let mainMeeting = List<Meeting>()
let meetingsWithOtherInfo = List<Meeting>()
override static func primaryKey() -> String? {
return "id"
}
}
</code></pre>
<p><strong> session 模型类</strong></p>
<pre><code>import Foundation
import RealmSwift
class Meeting: Object {
dynamic var id = 0
dynamic var name: String?
dynamic var created_at: String?
// other info
dynamic var restaurant_venue: String?
override static func primaryKey() -> String? {
return "id"
}
}
</code></pre>
<p>我正在像这样从我的服务器 API 中获取 <strong>约会</strong></p>
<pre><code>for fetchedAppointment in allAppointmentsFromAlamofire {
let existingAppointment: Results<(Appointment)>! = realm.objects(Appointment).filter("id = \(fetchedAppointment["id"]!)")
let newAppointment: Appointment = Appointment()
newAppointment.id = fetchedAppointment["id"]! as! Int
....
// add data to Meeting connected to Appointment
let newMeeting = Meeting()
newMeeting.id = fetchedAppointment["meetings"]["id"]! as! Int
...
// update or add new entry
try! realm.write {
print("NEW APPOINTMENT: \(newAppointment)")
realm.add(newAppointment, update: existingAppointment.count == 0 ? false : true)
}
}
</code></pre>
<p>每当程序尝试更新 Realm 中的现有条目时,就会出现错误 - 只要 existingAppointment 为 1。从我从 Github Realm 中读到的解决方法是删除 <strong>override static func primaryKey( )</strong> 在 session 课上。</p>
<p>如果我只是将新条目添加到约会中没有问题,但是如果我要更新,问题就会出现,如果我删除 session 类中的 primaryKey(),问题就会消失 ---- 但是,在我的应用程序的其他屏幕中,我真的需要在 session 类中拥有那个 primaryKey()。</p>
<p>我在这里疯狂的猜测是,每次我需要更新约会中的条目时,我也应该更新 session 。 </p>
<p>所以,问题是:为什么会发生这种情况?我的猜测正确吗?还有什么办法可以解决吗?</p></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>您似乎正在尝试使用不是其主键的值更新 newAppointment 对象。</p>
<pre><code>realm.add(newAppointment, update: existingAppointment.count == 0 ? false : true)
</code></pre>
<p>相反,Realm 希望您提供该对象的 key ,以便它可以更新指定的对象。</p>
<p>您似乎在此处设置键值,这是您应该用于更新的键值。</p>
<pre><code>let newAppointment: Appointment = Appointment()
newAppointment.id = fetchedAppointment["id"]! as! Int
</code></pre>
<p> <a href="https://realm.io/docs/swift/latest/#updating-objects" rel="noreferrer noopener nofollow">Realm documentation on updating with keys.</a> </p></p>
<p style="font-size: 20px;">关于ios - Realm Swift iOS - 无法设置主键,我们在Stack Overflow上找到一个类似的问题:
<a href="https://stackoverflow.com/questions/38091738/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/38091738/
</a>
</p>
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