.NetCore3.1獲取文件並重新命名以及大批量更新及寫入數據

using Microsoft.AspNetCore.Mvc;
using MySql.Data.MySqlClient;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace TestCoreDemo.Controllers
{
    using System.IO;
    using Microsoft.AspNetCore.Hosting;
    using Microsoft.Extensions.FileProviders;

    public class UpdateGalleryTypeController : Controller
    {
        private IWebHostEnvironment _env;
        private IFileProvider _fileProvider;
        public UpdateGalleryTypeController(IWebHostEnvironment env, IFileProvider fileProvider)
        {
            this._env = env; this._fileProvider = fileProvider;
        }
        public IActionResult Index()
        {
            string msg = "";
            //DoUpdateBigData(out msg);//--大批量更新數據
            //DoBigDataInsert(out msg);//-------大數據批量寫入
            string imgpath = Path.Combine(_env.WebRootPath, "smallimgs");
            string toFilePath = Path.Combine(_env.WebRootPath, "newFilePath");
            DirectoryInfo direcinfo = new DirectoryInfo(imgpath);
            if (direcinfo != null && direcinfo.Exists)
            {
                int index = 1100000;
                foreach (var item in direcinfo.GetFiles())
                {
                    if (item is FileInfo)
                    {
                        index += 1;
                        string fileExStr = Path.GetExtension(item.Name);
                        string newfilePath = Path.Combine(toFilePath, index + fileExStr);
                        System.IO.File.Copy(item.FullName, newfilePath);//---讀取一個文件夾下面的所有文件並命名
                    }
                }
            }

            ViewBag.result = msg;
            return View();

        }


        //*---通常我們平時需要一些比較大的測試數據，一次性寫入，或者寫入到隊列在持久化到數據庫，感覺寫入的效率差強人意(刷新數據庫只有幾十幾十的新增)
        //-----大批量的寫入數據，測試中發現平均一秒寫入的速度可達 400-500多條數據的樣子，應該還有更高效的方法，歡迎大家給出寶貴的建議！
        private void DoBigDataInsert(out string msg)
        {
            try
            {
                Stopwatch watch = new Stopwatch();
                watch.Start();
                string dbconnectionStr = "server=****;uid=fengge;pwd=qq88;port=3306;database=BigDataTest;sslmode=none;";
                StringBuilder sb = new StringBuilder();
                int index = 0;
                for (int i = 0; i < 1000000; i++)
                {
                    sb.Append("insert into Person(id,name,age)values('" + Guid.NewGuid().ToString() + "','name_" + new Random().Next(1, 99999) + "','" + new Random().Next(12, 38) + "');");
                    index = index + 1;
                    if (index % 500 == 0)
                    {
                        Task.Run(() => DoWork(sb.ToString(), dbconnectionStr)).Wait();
                        sb.Clear();
                    }
                }
                if (sb != null && sb.Length > 0)
                {
                    DoWork(sb.ToString(), dbconnectionStr);
                }
                msg = "ok";
                watch.Stop();
                ViewBag.totalTime = watch.Elapsed.TotalSeconds;
            }
            catch (Exception ex)
            {
                msg = ex.Message;
            }
        }

　　　　 //---比較高效一點的大批量修改數據
　　　　 //--應該還有更高效的方法，歡迎大家指出，謝謝
        private void DoUpdateBigData(out string msg)
        {
            try
            {
                string dbconnectionStr = "server=aaaa;uid=QQ;pwd=aa222;port=3306;database=zrfDb;sslmode=none;";
                using (yiyuneduContext db = new yiyuneduContext())
                {
                    var list = db.Gallery.Where(c => c.Gallerytype == null).Select(c => new { c.Galleryid, c.Gallerycontent });
                    StringBuilder sb = new StringBuilder();
                    int index = 0;
                    list.ToList().ForEach(c =>
                    {
                        var id = c.Galleryid;
                        string _type = c.Gallerycontent.Substring(c.Gallerycontent.LastIndexOf('.') + 1);
                        sb.Append("update gallery set gallerytype='" + _type + "' where galleryid='" + id + "';");
                        index = index + 1;
                        if (index % 200 == 0)
                        {
                            Task.Run(() => DoWork(sb.ToString(), dbconnectionStr)).Wait();
                            sb.Clear();
                        }
                        //update gallery set gallerytype=right(gallerycontent,3) where galleryid='FFA06D63-76E3-C31F-DE4B-EA30DAB78096';
                    });
                    if (sb != null && sb.Length > 0)
                    {
                        DoWork(sb.ToString(), dbconnectionStr);
                    }
                }
                msg = "ok";
            }
            catch (Exception ex)
            {
                msg = ex.Message;
            }
        }

        private void DoWork(string sql, string connectionDbStr)
        {
            using (MySqlConnection conn = new MySqlConnection(connectionDbStr))
            {
                conn.Open();
                using (MySqlCommand comm = new MySqlCommand())
                {
                    comm.CommandText = sql;
                    comm.CommandType = System.Data.CommandType.Text;
                    comm.Connection = conn;
                    comm.ExecuteNonQuery();
                }
            }
        }
    }
}