Question

我的问题是如何加入具有相同ID但联系人不同的所选行

这是我正在做的事情

的输出

|     Name     |    Address   |     Cellphone    |     Email      | 
|     John     |     NY       |       n/a        |   johndoe@y.c  |
|     John     |     NY       |    123456781     |       n/a      |

我希望我的输出是一个组合

|     Name     |    Address   |     Cellphone    |     Email      | 
|     John     |     NY       |     123456781    |   johndoe@y.c  |

这是我的Linq

var an = (from a in  db.Info
                     join b in db.Contact
                     on a.ID equals b.InfoID
                     where b.ContactTypeID == 56
                     || b.ContactTypeID == 59
                      select new
                                 {
                                     a.ID,
                                     a.LastName,
                                     a.FirstName,
                                     a.MiddleName,
                                     b.ContactTypeID,
                                     b.Values

                                 }).ToList();


            List<Info> wlist = new List<Info>();
            foreach (var row in an)
            {
                Info ci = new Info

                                           {

                                               ID = row.ID,
                                               Name = row.FirstName + " " + row.MiddleName + " " + row.LastName,
                                               ContactType = GetLookupDisplayValById(row.ContactTypeID),
                                               ContactValue = row.Values

                                           };
                wlist.Add(ci);
            }
            return Json(wlist.ToList(), JsonRequestBehavior.AllowGet);
        }

我希望有人可以帮助我

谢谢：）

Answer 1

你可以这样做：

from info in db.Info
join contact in db.Contact
on info.ID == contact.InfoID
select new Contact(info, contact)

你的构造函数将合并。

public class Contact
{
public int ID { get; set; }
public string LastName { get; set; }
public string MiddleName { get; set; }
public int ContactTypeID { get; set; }

public Contact(Info info, Contact contact)
{
   ID = info.ID;
   LastName = string.IsNullOrEmpty(info.LastName) ? contact.LastName : info.LastName;
}
}

Answer 2

尝试使用GroupBy

var resuts = db.Info.GroupBy(i=>i.ID)
 .Select(g=>new Info{
            ID = g.Key,
            Address = g.Fist().Address,
            Cellphone = g.FistOrDefault(x=> x.Cellphone !="n/a"),
            Email = g.FistOrDefault(x=> x.Email !="n/a")
        }).ToList();

在Linq中加入2个具有相同ID的列

2 个答案: