问题:Vapor 3 PostgreSQL CRUD 没有请求 http

我正在使用 Xcode 11.2 和 Swift 5.1 基于 Vapor 3.1.10 创建后端,数据库是 PostgreSQL 12。我有一个问题:如何在没有 POST 和 GET 请求的情况下与数据库(CRUD)交互。所有教程都展示了如何仅基于请求通过 HTTPS 进行 CRUD。但是,如果我的应用需要在不与网络交互的情况下将某些内容保存在数据库中怎么办?看我的代码:

import Vapor
import FluentPostgreSQL

final class Device: PostgreSQLModel {        
    var id: Int?
    var isWorking: Bool
    var serial: Int

    init(isWorking: Bool, serial: Int) {
        self.isWorking = isWorking
        self.serial = serial
    }    
}
extension Device: Content {}
extension Device: Migration {}
extension Device: Parameter {}

经典的写或读方法是:

import Vapor

final class DeviceController {        
    func readAll(_ req: Request) throws -> Future<[Device]> {
        return Device.query(on: req).all()
    }

    func create(_ req: Request) throws -> Future<Device> {
        return try req.content.decode(Device.self).flatMap { device in
            return device.save(on: req)
        }
    }
}

如何将req替换为另一个可以在本地创建的后台安全线程?

例如:

let device = Device(isWorking: true, serial: 54321)
device.save(on: <#T##DatabaseConnectable#>)

如何更换<#T##DatabaseConnectable#>?

我将感谢任何帮助或建议。

解答

基于这个问题和答案(Is is possible to use Vapor 3 Postgres Fluent in a Standalone script?)我实现了这样的 CRUD:

import Vapor
import FluentPostgreSQL

final class Device: PostgreSQLModel {
    var id: Int?
    var isWorking: Bool
    var serial: Int

    init(isWorking: Bool, serial: Int) {
        self.isWorking = isWorking
        self.serial = serial
    }
}
extension Device: Content {}
extension Device: Migration {}
extension Device: Parameter {}

final class WorkWithPostgres {

    let databaseConfig = PostgreSQLDatabaseConfig(hostname: "localhost", port: 5432, username: "username", database: "testestest", password: nil)

    let database: PostgreSQLDatabase

    static let shared = WorkWithPostgres()

    private init() {
        database = PostgreSQLDatabase(config: databaseConfig)
    }

    func readAll<T: PostgreSQLModel>(postgreSQLModel: T.Type, completion: (([T]) -> Void)?) {
        let worker = MultiThreadedEventLoopGroup(numberOfThreads: 1)
        let conn = database.newConnection(on: worker)

        let _ = conn.map { connection in
            postgreSQLModel.query(on: connection).all().map { databaseData in
                worker.shutdownGracefully { _ in
                }

                completion?(databaseData)
            }
        }
    }

    func create<T: PostgreSQLModel>(postgreSQLModel: T) {
        let worker = MultiThreadedEventLoopGroup(numberOfThreads: 1)
        let conn = database.newConnection(on: worker)

        let _ = conn.map { connection in
            let _ = postgreSQLModel.save(on: connection).whenComplete {
                worker.shutdownGracefully { _ in
                }
            }
        }
    }

}

final class DeviceController {

    func readAll(completion: (([Device]) -> Void)?) {
        WorkWithPostgres.shared.readAll(postgreSQLModel: Device.self) { devices in
            completion?(devices)
        }
    }

    func create(isWorking: Bool, serial: Int) {
        let device = Device(isWorking: isWorking, serial: serial)

        WorkWithPostgres.shared.create(postgreSQLModel: device)
    }

}

它正在工作,但我不确定它是否是这样做的好方法。有人知道吗?