ef 两表join

linq写法：

//linq写法
var query = (from u in oae.Users
                join p in oae.User_Parent on u.Id equals p.UsersId
                select new
                {
                    username = u.UserName,
                    fahter = p.Father,
                    mother = p.Mother
                }).ToList();

lamdba写法：

   /*
    *  第一个参数  ：   join的表
    *  第二，三参数：   join的参数
    *  第四个参数  ：   返回值
    *
    */
List<UserViewModel> result = oae.Users.Join(oae.User_Parent, a => a.Id, b => b.UsersId, (u, p) => new UserViewModel
                            {
                                UserName = u.UserName,
                                Father = p.Father,
                                Mother = p.Mother
                            }).ToList();