Question

有没有办法为具有可选属性的Realm类创建复合键？

例如：

class Item: Object {
    dynamic var id = 0
    let importantNumber = RealmOptional<Int>()
    let importantNumber2 = RealmOptional<Int>()

    func setCompoundID(id: Int) {
        self.id = id
        compoundKey = compoundKeyValue()
    }

    func setCompoundImportantNumber(importantNumber: Int) {
        self.importantNumber = importantNumber
        compoundKey = compoundKeyValue()
    }

    func setCompoundImportantNumber2(importantNumber2: Int) {
        self.importantNumber2 = importantNumber2
        compoundKey = compoundKeyValue()
    }

    dynamic lazy var compoundKey: String = self.compoundKeyValue()

    override static func primaryKey() -> String? {
        return "compoundKey"
    }

    func compoundKeyValue() -> String {
        return "\(id)\(importantNumber)\(importantNumber2)"
    }
}

当我编写这样的代码时，编译器会抱怨我无法分配给我的常量属性，并建议我更改“让”和“＃”;到＆＃39; var＆＃39 ;;但是，根据Realm Swift Documentation，我需要将可选属性设置为常量。

我不确定这是否可行，因为我无法在Realm文档中找到有关可选主键的任何内容。

Answer 1

您需要设置RealmOptional＆n; value成员。 RealmOptional属性不能为var，因为Realm无法检测到Objective-C运行时无法表示的属性类型的分配，这就是RealmOptional，List的原因LinkingObjects属性必须全部为let。

class Item: Object {
    dynamic var id = 0
    let importantNumber = RealmOptional<Int>()
    let importantNumber2 = RealmOptional<Int>()

    func setCompoundID(id: Int) {
        self.id = id
        compoundKey = compoundKeyValue()
    }

    func setCompoundImportantNumber(importantNumber: Int) {
        self.importantNumber.value = importantNumber
        compoundKey = compoundKeyValue()
    }

    func setCompoundImportantNumber2(importantNumber2: Int) {
        self.importantNumber2.value = importantNumber2
        compoundKey = compoundKeyValue()
    }

    dynamic lazy var compoundKey: String = self.compoundKeyValue()

    override static func primaryKey() -> String? {
        return "compoundKey"
    }

    func compoundKeyValue() -> String {
        return "\(id)\(importantNumber)\(importantNumber2)"
    }
}

用于可选属性的Realm Swift复合键

1 个答案: