EF 增删改查
StudentEntities entities = new StudentEntities(); //初始化对象Register register = new Register();#region 增加//register.UserName = "张三";//register.Pwd = "123";//register.Sex = "男";//register.Phone = "123456";//register.Age = "20";//register.Address = "河南郑州";//entities.Register.Add(register); //添加一个集合使用Add//entities.SaveChanges(); //保存#endregion#region 删除//Register r = entities.Register.Where(i=>i.Id==39).SingleOrDefault(); //在这里需要注意的是Lambda表达式的i属性Register,它是一个集合,所以需要它.出来他的id项//entities.Register.Remove(r); //删除使用的是Remove//entities.SaveChanges();#endregion#region 修改//Register rr = entities.Register.Where(i => i.Id == 40).SingleOrDefault(); //修改时间记得先查询要修改的条件//rr.UserName = "zhangsan"; //在这里需要注意的是接受的对象//rr.Pwd = "456";//rr.Sex = "女";//rr.Phone = "123456789";//rr.Age = "20";//rr.Address = "北京";//entities.SaveChanges(); //保存#endregion#region 查询//Register rrr = entities.Register.Where(i => i.Id == 41).SingleOrDefault();//Console.WriteLine("{0},{1},{2}",rrr.Id,rrr.UserName,rrr.Pwd);//Register rrr = entities.Register.SelectMany(i=>i.Id==40&&i.Id==41).SelectMany();
转载于:https://www.cnblogs.com/laopo/p/5133475.html
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