没有 http 请求的 Vapor 4 PostgreSQL CRUD [英] Vapor 4 PostgreSQL CRUD without http requests

问题描述

我正在使用 Swift 5 和 Vapor 4 编写后端，数据库是 PostgreSQL 12.我有一个问题:如何在没有 POST 或 GET 请求的情况下在本地与数据库 (CRUD) 交互?所有教程再次展示了如何仅基于请求通过 HTTPS 进行 CRUD.我已经问过这个问题:Vapor 3 PostgreSQL CRUD without requests http但这不是一个重复的问题，Vapor 4 的工作原理完全不同！请看看我目前的 Vapor 3 工作班级(基于这个答案:是否可以在独立脚本中使用 Vapor 3 Postgres Fluent?):

I am writing backend using Swift 5 and Vapor 4, database is PostgreSQL 12. I have a question: how to interact with database (CRUD) locally, without POST or GET requests? All tutorials show how to CRUD only based on Request through HTTPS again. I already asked this question: Vapor 3 PostgreSQL CRUD without requests http BUT IT'S NOT A DUPLICATE QUESTION, Vapor 4 works completely different! Please, look at my current, working class for Vapor 3 (based on this answer: Is is possible to use Vapor 3 Postgres Fluent in a standalone script?):

import Vapor
import FluentPostgreSQL

final class WorkWithPostgres {
    
    private let databaseConfig = PostgreSQLDatabaseConfig(hostname: "localhost", port: 5432, username: "RutrackerTech", database: "vaporpostgres", password: "ru628trac4er")
    
    let postgres: PostgreSQLDatabase
    
    static let shared = WorkWithPostgres()
    
    private init() {
        postgres = PostgreSQLDatabase(config: databaseConfig)
    }
    
    /// Will it create undeleted memory leaks?
    func shutdownGracefully(worker: MultiThreadedEventLoopGroup, completion: (() -> Void)?) {
        worker.shutdownGracefully { error in
            completion?()
        }
    }
    
    /// Will it create udeleted memory leaks?
    func connect(completion: ((MultiThreadedEventLoopGroup, PostgreSQLConnection) -> Void)?) {
        let worker = MultiThreadedEventLoopGroup(numberOfThreads: 1)
        let eventLoopFuturePostgreSQLConnection = postgres.newConnection(on: worker)
        let _ = eventLoopFuturePostgreSQLConnection.map { postgreSQLConnection in
            completion?(worker, postgreSQLConnection)
        }
    }
    
    func readAll<T: PostgreSQLModel>(postgreSQLModel: T.Type, completion: (([T]) -> Void)?) {
        connect { worker, connection in
            let _ = postgreSQLModel.query(on: connection).all().map { databaseData in
                self.shutdownGracefully(worker: worker) {
                    completion?(databaseData)
                }
            }
        }
    }
    
    func create<T: PostgreSQLModel>(postgreSQLModel: T) {
        connect { worker, connection in
            let _ = postgreSQLModel.save(on: connection).whenComplete {
                self.shutdownGracefully(worker: worker, completion: nil)
            }
        }
    }
    
}

最大的问题:我在 FluentPostgresDriver 或 Fluent 中找不到 PostgreSQLDatabase 的替代品.或者，也许，应该是解决此任务的另一种方法?

The biggest problem: I cannot find replacement to PostgreSQLDatabase in FluentPostgresDriver or in Fluent. Or, maybe, should be another approach to solve this task?

感谢您的阅读，如果您有任何帮助或建议，我将不胜感激！

Thank you for reading, I will be thankful for any help or advice!

推荐答案

所以，正确的想法是不要像使用 Vapor 3 那样使用数据库.现在，在 Vapor 4 中，您应该使用 Database实例.从哪里得到它?我可以为您推荐 2 个选项.首先是 boot.swift 中的 boot(_ app: Application) 或 configure.swift 中的 configure(_ app: Application).所以 app 将有选项来处理这样的数据库:<Model>.query(on: app.db).第二个选项是任何请求中的 req.req 应该是 Request 类型，像这样:.query(on: req.db).通过Model，你可以取任何继承自Model类的类，例如:final class User: Model, Content { 你应该组织你的代码从 boot.swift 或 configure.swift 或任何请求调用，例如，在 routes.swift

So, correct idea not to work with database like I did with Vapor 3. Now, in Vapor 4, you should use Database instance. Where to get it? I can suggest 2 options for you. First is boot(_ app: Application) in boot.swift or in configure(_ app: Application) in configure.swift. So app will have options to work with database like this: <Model>.query(on: app.db). Second option is req in any request. req should be of type Request, like this: <Model>.query(on: req.db). By Model, you can take any class inherited of class Model, for example: final class User: Model, Content { You should organise your code to be called from boot.swift or configure.swift or from any request, for example, in routes.swift

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