在关系方面,我来自类似 Ruby on Rails 的数据结构。
所以在 Rails 中:Foo 有很多 Bars 而 Bar 有一个 Foo。
通过 RealmSwift 文档,我想到了这个,我认为:
class Foo: Object {
// other props
var bars = List<Bar>() // I hope this is correct
}
class Bar: Object {
// other props
@objc dynamic var foo: Foo?
}
如果以上是正确的,我很难知道如何创建这个关系对象。
// I need to create Foo before any Bar/s
var foo = Foo()
foo.someProp = "Mike"
var bars = [Bar]()
var bar = Bar()
bar.someProp1 = "some value 1"
bars.insert(bar, at: <a-dynamic-int>)
这是我完全停止的地方:
// Create Foo
try! realm.write {
realm.add(foo)
// But.... I need to append bars, how?
}
try! realm.write {
for bar in bars {
// realm.add(bar)
// I need to: foo.append(bar) but how and where?
}
}
最后,我应该能够通过 foo.bars
查看 bars
和 bar.foo
的数组来获取 富
foo
和 bar
尚未创建,因此不知道如何链接该批处理以立即保存。可能的?如何?如果您提供答案,您可以发布对文档的引用以供将来引用吗?这对我来说算是一个答案。谢谢
最佳答案
这应该让你开始:
class Foo: Object {
// other props
@objc dynamic var id = ""
let bars = List<Bar>()
override static func primaryKey() -> String? {
return "id"
}
}
class Bar: Object {
// other props
@objc dynamic var id = ""
let foo = LinkingObjects(fromType: Foo.self, property: "bars")
override static func primaryKey() -> String? {
return "id"
}
}
let foo = Foo()
foo.id = "somethingUnique"
foo.someProp = "Mike"
let bar = Bar()
bar.id = "somethingUnique"
bar.someProp1 = "some value 1"
try! realm.write {
realm.add(foo)
realm.add(bar)
foo.bars.append(bar)
}
let anotherBar = Bar()
anotherBar.id = "somethingUnique"
anotherBar.someProp1 = "some other value"
try! realm.write {
realm.add(anotherBar)
foo.bars.append(anotherBar)
}
其他地方:
var currentBars: List<Bar>()
if let findFoo = realm.object(ofType: Foo.self, forPrimaryKey: "someUniqueKey") {
currentBars = findFoo.bars
// to filter
if let specificBar = currentBars.filter("id = %@", id) {
// do something with specificBar
}
}
从 bar 获取 foo:
if let bar = realm.object(ofType: Bar.self, forPrimaryKey: "theUniqueID") {
if let foo = bar.foo.first {
// you have your foo
}
}
如果我没有正确理解您的评论:
// already created foo
for nonRealmBar in nonRealmBars {
// Note: you could also use realm.create
let bar = Bar()
bar.id = nonRealmBar.id
bar.someProp = nonRealmBar.someProp
// fill in other properties;
try! realm.write {
realm.add(bar)
foo.bars.append(bar)
}
}
关于swift - 使用 RealmSwift 保存一对多关系对象,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/54725688/