C#EF_core的添加删除修改

第一步：添加EF_CORE的引用using Microsoft.EntityFrameworkCore;

第二步：创建数据库连接

    /// <summary>
    /// 创建EF的上下文
    /// </summary>
   public class HDbContent:DbContext
    {
        public HDbContent() { }
        public HDbContent(DbContextOptions<HDbContent> options) : base(options) { }
        public DbSet<Setting> Setting { get; set; }
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            if (!optionsBuilder.IsConfigured)
            {
                optionsBuilder.UseMySQL(@"Datasource=localhost;Database=qhserver;uid=root;pwd=123456;Character Set=utf8;Allow User Variables=True");
            }
        }
         public class Setting
   {
        public int Id { get; set; }
        public string QHISDN { get; set; }
        public string LocalAddress { get; set; }
        public string LocalPort { get; set; }
        public string SmsIP { get; set; }
        public string SmsProt { get; set; }
   }
    }

  static void Main(string[] args)
        {
            using (var db=new HDbContent())
            {
                //Console.WriteLine("Insert a new Setting");
                //db.Setting.Add(new Setting { Id = 3, QHISDN = "15726660396", LocalAddress = "192.168.1.130", LocalPort = "19202", SmsIP = "192.168.1.100", SmsProt = "6060" });
                //if (db.SaveChanges() > 0)
                //    Console.WriteLine("Insert Success!");
                //else
                //    Console.WriteLine("Insert Error!");
                //Console.WriteLine("Read for a Setting");
                

            }
            using (var db=new HDbContent())
            {
                List<Setting> settings = db.Setting.ToList();
                foreach (var item in db.Setting.ToList())
                {
                    Console.WriteLine(item.QHISDN);
                }  
            }
            Console.WriteLine("Hello World!");
        }