通过不同属性订购核心数据实体，但在同一级别

发布于 2025-01-23 00:58:01 字数 910 浏览 1 评论 0原文

我有一个称为联系人的实体，其中包含多个属性，包括fivenname，agrommyname和familyname。我想通过fivenname订购它们，然后familyName。但是，某些实体可能没有fivenname或familyName，但具有agrommy> agrommistionName。在排序联系人时，我想将实体订购为agrommandname and fivenname，其中相同的属性，例如，如果没有gishivename，则使用组织名称。

目前我有：

    let fetchRequest: NSFetchRequest<Contact> = Contact.fetchRequest()
    fetchRequest.sortDescriptors = [
        NSSortDescriptor(key: "givenName", ascending: true),
        NSSortDescriptor(key: "organizationName", ascending: true),
        NSSortDescriptor(key: "familyName", ascending: true)
        ]

我会写类似的东西：

order by IS_EMPTY(IS_EMPTY(givenName, lastName), organizationName) ASC

如何用Swift和Core Data表达出来？

原文

I have an entity called Contact with multiple attributes, including givenName, organizationName and familyName. I want to order them by givenName and then familyName. However, some entities may not have givenName or familyName but have organizationName. When sorting the Contacts I want to order the entities as organizationName and givenName where the same attribute, e.g. use organizationName when givenName is not available.

Currently I have:

    let fetchRequest: NSFetchRequest<Contact> = Contact.fetchRequest()
    fetchRequest.sortDescriptors = [
        NSSortDescriptor(key: "givenName", ascending: true),
        NSSortDescriptor(key: "organizationName", ascending: true),
        NSSortDescriptor(key: "familyName", ascending: true)
        ]

I would write something similar like:

order by IS_EMPTY(IS_EMPTY(givenName, lastName), organizationName) ASC

How can I express that with Swift and Core Data?

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朕就是辣么酷 2025-01-30 00:58:01

您需要的自定义越多，您必须编写的代码越多。

nssortDescriptor为自定义比较器提供了初始化器，

let myComparator : (Any, Any) -> ComparisonResult = { lhs, rhs in
    let lhs = lhs as! Contact
    let rhs = rhs as! Contact
    if !lhs.givenName.isEmpty { return lhs.givenName.localizedCaseInsensitiveCompare(rhs.givenName) }
    if !lhs.organizationName.isEmpty { return lhs.organizationName.localizedCaseInsensitiveCompare(rhs.organizationName) }
    return lhs.familyName.localizedCaseInsensitiveCompare(rhs.familyName)
}

let mySortDescriptor = NSSortDescriptor(key: nil, ascending: true, comparator: myComparator)

The more customization you need the more code you have to write.

NSSortDescriptor provides an initializer for a custom comparator, something like this

let myComparator : (Any, Any) -> ComparisonResult = { lhs, rhs in
    let lhs = lhs as! Contact
    let rhs = rhs as! Contact
    if !lhs.givenName.isEmpty { return lhs.givenName.localizedCaseInsensitiveCompare(rhs.givenName) }
    if !lhs.organizationName.isEmpty { return lhs.organizationName.localizedCaseInsensitiveCompare(rhs.organizationName) }
    return lhs.familyName.localizedCaseInsensitiveCompare(rhs.familyName)
}

let mySortDescriptor = NSSortDescriptor(key: nil, ascending: true, comparator: myComparator)

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