Question

我尝试接受JSON响应，反序列化并存储在localdb中。一切正常，但它没有将数据写入我的数据库。我似乎无法弄清楚为什么我没有收到任何错误。

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using DataFetcher.DataFieldsInClasses;
using DataFetcher.EF_Models;
using Newtonsoft.Json;


namespace DataFetcher
{
    class Program
    {
        static void Main(string[] args)
        {
            var teamNames = new TeamsList();
            teamNames.teamList.Sort();

            for (int i = 0; i < 30; i++)
            {
                var cities = teamNames.teamList.ElementAt(i);
                //URL for each indivual team
                string URL = @"http://nhlwc.cdnak.neulion.com/fs1/nhl/league/teamroster/" + cities + "/iphone/clubroster.json";
                WebRequest wrGETURL;
                wrGETURL = WebRequest.Create(URL);
                HttpWebResponse response = wrGETURL.GetResponse() as HttpWebResponse;

                StreamReader responseStream = new StreamReader(response.GetResponseStream());

                var result = responseStream.ReadToEnd();
                //var parsedInformation = JsonConvert.DeserializeObject<RootObject>(result);
                foreach (var forwardData in JsonConvert.DeserializeObject<RootObject>(result).forwards)
                {
                    //test output
                    Console.WriteLine(forwardData.id + " " + " " + forwardData.position + " " + forwardData.name + " " + forwardData.twitterURL + " " + forwardData.height + " " + forwardData.birthdate);

                    //write to database using EF
                    using (var _temp_Player = new DataFetcherDBEntities())
                    {
                        //var players = _temp_Player.Set<Player>();
                        _temp_Player.Players.Attach(new Player
                        {
                            player_id = forwardData.id,
                            name = forwardData.name,
                            age = forwardData.age,
                            birthdate = forwardData.birthdate,
                            birthplace = forwardData.birthplace,
                            weight = forwardData.weight,
                            height = forwardData.height,
                            number = forwardData.number,
                            position = forwardData.position,
                            imageUrl = forwardData.imageUrl,
                            twitterURL = forwardData.twitterURL,
                            twitterHandle = forwardData.twitterHandle
                        });
                        _temp_Player.SaveChanges();
                    }

                }

            }
            Console.ReadKey();

        }
    }
}

任何提示/想法？
P.S我还在学习和自学。

*编辑，我将localdb复制到＆＃34; ... DataFetcher \ bin \ Debug \ Databases＆＃34;我的新错误是＆＃34;＆＃34;违反PRIMARY KEY约束＆＃39; PK__tmp_ms_x__44DA120C6655986D＆＃39;。无法在对象＆＃39; dbo.Player＆＃39;中插入重复键。重复键值为（8473492）。\ r \ n语句已终止。＆＃34;}＆＃34; 这对我来说没有意义，因为每个玩家都有一个唯一的ID（player_id = forwardData.id）

Answer 1

您需要使用_temp_Player.Players.Add而不是Attach。

当您执行附加时，您需要为EF设置实体状态，以检测它是否为新记录，并在保存更改期间将其插入数据库。

实体框架不写入数据库

1 个答案: