swift Vapor - 操作无法完成。 （MySQL.Error错误4.）

Question

我不断收到此错误。

我确认mysql服务器正在我的MAC机器上运行，并且我在这个项目的mysql服务器上创建了一个数据库。

1. 下面是我main.swift

import Vapor 
import VaporMySQL 

let drop = Droplet() 

try drop.addProvider(VaporMySQL.Provider.self) 

drop.preparations = [Student.self] 

let _ = HomeController(drop: drop) 

drop.run() 

下面是我HomeController.swift

import Vapor 
import HTTP 
import Foundation 

final class HomeController { 

    var drop: Droplet 

    init(drop: Droplet) { 
     self.drop = drop 

    let studentsGroup = self.drop.grouped("/") 
    studentsGroup.get(handler: homePageWithBankList) 
    } 

    func homePageWithBankList(request: Request) throws -> ResponseRepresentable { 

    do { 
     var student = Student() 
     student.name = "name" 
     try student.save()   // Here error raise 
    } catch { 
     print(error.localizedDescription) // Getting error log here 
    } 

    return "" 

    } 
} 

下面是我Student.swift模型类

import Vapor 

final class Student: Model { 

    var id: Node? 
    var exists: Bool = false 

    var name: String = "" 

    init() { 
     self.id = nil 
    } 

    init(node: Node, in context: Context) throws { 
     id = try node.extract("id") 
     name = try node.extract("name") 
    } 

    public func makeNode(context: Context) throws -> Node { 
     return try Node(node:[ 
      "id": id, 
      "name": name 
      ]) 
    } 

    static func prepare(_ database: Database) throws { 
     try database.create("student") { student in 
      student.id() 
      student.string("name") 
     } 
    } 

    static func revert(_ database: Database) throws { 
     try database.delete("student") 
    } 

} 

下面是mysql.json配置文件

{ 
    "host": "localhost", 
    "user": "root", 
    "password": "admin", 
    "database": "studentsDB", 
    "port": "3306", 
    "encoding": "utf8" 
} 

下面是我的包依赖性

dependencies: [ 
     .Package(url: "https://github.com/vapor/vapor.git", majorVersion: 1, minor: 5), 
     .Package(url: "https://github.com/vapor/mysql-provider.git", majorVersion: 1, minor: 1) 
    ] 

下面是在我的MAC

运行MySQL --version

mysql Ver 14.14 Distrib 5.7.17, for osx10.12 (x86_64) using EditLine wrapper 

编辑： - 我有在GitHub上>>Here<<这个项目

Answer 1

所以这是一个初学者的错误:)

首先，更改

do { 
     var student = Student() 
     student.name = "name" 
     try student.save()   // Here error raise 
    } catch { 
     print(error.localizedDescription) // Getting error log here 
    } 

到

var student = Student() 
student.name = "name" 
do { 
    try student.save() 
} catch { 
    print(error) 
} 

，看看有什么地方出了错

所以，你尝试使用学生 - 表，但创建学生在您的准备。

变化

try database.create("student") { student in } ... 

到

try database.create("students") { student in } ... 

否则，您可以用

final class Student: Model { 
    static var entity = "student"  
    ... 
} 

总是好的指定模型的声明中的表名来看看文档

Vapor Documentation