EntityFramework

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace EFSQLserver
{
    class Program
    {
        static void Main(string[] args)
        {
            using(ScadaDataEntities1 context = new ScadaDataEntities1())//数据库名
            {
                context.Database.Log += c => Console.WriteLine($"sql:{c}");
                //类型为表名
                ActualData actualData1 = context.ActualDatas.Find(1);//找出主键为1 即使查询

                //针对数据库的查询
                ActualData actualData2 = context.ActualDatas.FirstOrDefault(u => u.Id == 1);

                //new List<int>().FirstOrDefault(u=>u<10);//针对内存数据的Linq to object

                //延时查询
                var actualDataList = context.ActualDatas.Where(u => u.Id > 10&& u.Id <100 && u.VarName.Length>8);

                //actualData1.VarName += "test"; //修改数据中的数据并保存

                //foreach (var item in actualDataList)
                //{
                //    Console.WriteLine(item.VarName);
                //}

                ActualData actualDataNew = new ActualData()
                {
                    InsertTime = DateTime.Now,//Convert.ToDateTime("2005-11-6 16:11:04"),
                    Value = "5",
                    VarName = "test",
                    Remark = "这是测试"
                };

                context.ActualDatas.Add(actualDataNew);
                context.SaveChanges();

                ActualData actualData3 = context.ActualDatas.FirstOrDefault(u => u.Remark == "这是测试");
                Console.WriteLine(actualData3);
                Console.ReadKey();
            }
        }
    }
}