接注冊(cè)完成我們來(lái)完成用戶登陸：郵箱作為賬戶

1. 注冊(cè)路由：

SKUserController中添加function：   
 public func login(req: Request)throws-> EventLoopFuture<String>{
...
}

 router.get("login", use: SKUserController().login)

2. 用戶登陸很常規(guī)會(huì)遇到幾個(gè)常規(guī)問(wèn)題：
   · 賬戶不存在
   . 賬戶存在密碼不正確

public func login(req: Request)throws-> EventLoopFuture<String>{
        struct InnerUser: Content{
            var email: String
            var password: String
        }
        
        let user = try! req.query.decode(InnerUser.self)
     return   SKUser.query(on: req).group(SQLiteBinaryOperator.or) { (or) in
            or.filter(\.email, SQLiteBinaryOperator.equal, user.email)
            }.all().flatMap { (us) -> EventLoopFuture<String> in
                let result = req.eventLoop.newPromise(String.self)

                if us.isEmpty {
                    result.succeed(result: "用戶不存在")
                    return result.futureResult
                }else{
                    
                    if us.first!.password.elementsEqual(user.password.md5Base64) {
                        
                        result.succeed(result: "登陸成功:\(us.first!)")
                    }else{
                        result.succeed(result: "密碼錯(cuò)誤")
                    }
                    return result.futureResult
                }
        }
        
    }