using your models and maps their fields efficiently to the underlying storage. Objects managed by SwiftData are fetched from the database when needed and automatically saved at the right moment, with no additional work on your part. You can also take full control using the ModelContext API. ...
funcbirthYearCountByKit()->[Int:Int]{letfetchRequest=NSFetchRequest<NSFetchRequestResult>(entityName:"Student")fetchRequest.propertiesToGroupBy=["birthOfYear"]fetchRequest.sortDescriptors=[NSSortDescriptor(key:"birthOfYear",ascending:true)]fetchRequest.resultType=.dictionaryResultTypeletexpressDescription=NSEx...
如果我们不使用lazy,那么fetchUsername()将在 state 的所有三种情况下都被调用,即使在一种情况下它没有被使用。 如果我们删除lazy并将对fetchUsername()的调用放在两个 case 中,那么我们将复制代码——对于简单的单行代码来说这不是一个大问题,但你可以想象这将在更复杂的代码中如何引起问题。 如果我们将user移到...
Learn how you can harness the power of SwiftData in your app. Find out how ModelContext and ModelContainer work together to persist your app's data. We'll show you how to track and make your changes manually and use SwiftData at scale with FetchDescriptor, SortDescriptor, and enumerate. ...
{returnnil}returnUIImage(data:imageData)}/// Is cached image currently availablestaticvarcachedDoggyAvailable:Bool{cachedDoggy!=nil}/// Call the Dog API and then download and cache the dog imagestaticfuncfetchRandomDoggy()asyncthrows->UIImage{leturl=URL(string:"https://dog.ceo/api/breeds/...
Swift开发中常用的数据库包括Core Data、SQLite、Realm。Core Data是苹果官方提供的持久化框架,具备强大的数据建模和查询功能,适合大型应用中的复杂数据管理。SQLite是一个轻量级的关系型数据库,适合需要高性能和灵活性的应用。Realm是一个高性能的移动数据库,提供了简洁的API和强大的查询功能。接下来,我们将详细探讨每...
public protocol Authorizer { func fetchAuthValue(socketID: String, channelName: String, completionHandler: (PusherAuth?) -> ()) } where PusherAuth is defined as: public class PusherAuth: NSObject { public let auth: String public let channelData: String? public let sharedSecret: String? public...
fetchAll(From<Person>()) Fetching objects (complex): let people = try dataStack.fetchAll( From<Person>() .where(\.age > 30), .orderBy(.ascending(\.name), .descending(.\age)), .tweak({ $0.includesPendingChanges = false }) ) Querying values: let maxAge = try dataStack.query...
从Oracle Content Management下载页下载 Oracle Content Management 示例资产包 (OCESamplesAssetPack.zip)。将下载的 zip 文件解压缩到计算机上的某个位置。提取之后,此位置将包含一个名为 OCEGettingStarted_data.zip 的文件。 作为管理员登录 Oracle Content Management Web 界面。
The goal here is to create a custom fetch request to read the whole collection of results, then simply return the first one to get your data, or create a fresh instance if there was nothing already saved.As an example, we might have an AppSettings model such as this one:...