使用RealmSwift保存一对多关系对象

在关系方面，我来自一个类似RubyonRails的数据结构

所以在Rails中：Foo有很多条，Bar有一条Foo

通过查阅RealmSwift文档，我想到了这个，我想：

class Foo: Object {
  // other props
  var bars = List<Bar>() // I hope this is correct
}

class Bar: Object {
  // other props
  @objc dynamic var foo: Foo?
}

最后，我应该能够

foo.bar

查看

bar

数组，并

bar.foo

获取

foo

---

foo

和

bar

尚未创建，因此不知道如何链接批次以立即保存。可能的怎么用？如果您提供的是答案，您是否可以发布文档参考以供将来参考？这对我来说算是一个答案。谢谢

这应该让您开始：

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)
}

如果我正确理解您的评论：

// 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)
    }
}

---

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)
}

如果我正确理解您的评论：

// 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)
    }
}

if let bar = realm.object(ofType: Bar.self, forPrimaryKey: "theUniqueID") {
    if let foo = bar.foo.first {
        // you have your foo
    }
}

// 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)
    }
}