EF-增删改查简单示例

标签：ef   curd   增删改查   

前言：

数据上下文： NorthwindContext，

数据成员对象：

public class Province（）{...}

1，新增

 Province province = new Province { ProvinceID = Guid.NewGuid(), ProvinceNo = "100000", ProvinceName = "北京" };
            using (NorthwindContext db = new NorthwindContext())
            {
                db.Provinces.Add(province);
                db.SaveChanges();
            }

Province province = new Province { ProvinceID = new Guid("F0427980-6CB6-4D5B-91F5-ADE3E676DEA1"), ProvinceNo = "100000", ProvinceName = "上海" };
            using (NorthwindContext db = new NorthwindContext())
            {
                db.Entry(province).State = EntityState.Modified;
                db.SaveChanges();
            }

Province province = new Province { ProvinceID = new Guid("F0427980-6CB6-4D5B-91F5-ADE3E676DEA1") };
            using (NorthwindContext db = new NorthwindContext())
            {
                db.Provinces.Attach(province);
                db.Provinces.Remove(province);
                db.SaveChanges();
            }

using (NorthwindContext db = new NorthwindContext())
            {
                var expr = from p in db.Provinces
                           select p;

                foreach (var item in expr)
                {
                    Console.WriteLine("{0}-{1}-{2}", item.ProvinceID, item.ProvinceNo, item.ProvinceName);
                }
            }

EF-增删改查简单示例

标签：ef   curd   增删改查   

原文地址：http://blog.csdn.net/rj532029887/article/details/42079519