lambda表达式中Join的问题

[rockmmm]

         //车手类
	public class Player
	{
		public Player(string name,int age,string country,string[] cars,int[] winYears)
		{
			Name = name;
			Age = age;
			Country = country;
			Cars = cars;
			WinYears = winYears;
		}
		public string Name{get;set;}
		public int Age{get;set;}
		public string Country{get;set;}
		public string[] Cars{get;set;}
		public int[] WinYears{get;set;}
	}
         //厂商与车名对应类
	public class MadeFac
	{
		public MadeFac(string name,string car)
		{
			Name = name;
			Car = car;
		}
		public string Name{get;set;}
		public string Car{get;set;}
	}
	List<Player> lp = new List<Player>();
	lp.Add(new Player("Zhang Si",22,"China",new string[]{"911","Benz"},new int[]{1978,1992,1993}));
	lp.Add(new Player("Zhang Wu",26,"China",new string[]{"F1","Buick"},new int[]{1977,2004}));
         ............
	List<MadeFac> mf = new List<MadeFac>();
	mf.Add(new MadeFac("FC1","F1"));
	mf.Add(new MadeFac("FC2","911"));
         ............
         //下面是查询部份，也是要提问的部份
	var query8 = lp.SelectMany(r=>r.Cars,(r,c)=>new {Player = r,Car = c}).
			Join(mf,r1=>r1.Car,r2=>r2.Car,(r1,r2)=>new {Name = r1.Player.Name,Car = r1.Car,Fac = r2.Name}).
			GroupBy(r=>r.Name);

	foreach(var q in query8)
	{
		Console.WriteLine("车手:["+q.Key+"]");
		foreach(var p in q)
			Console.WriteLine(p.Car+":"+p.Fac);
		Console.WriteLine();
	}		

请问上面的查询部份，上面的查询代码如何修改，让它车子在无对应厂商时，依然显示出来，并且厂商的对应名称为空。请用lambda表达式

[wuyq11]

LINQ使用JOIN
var q =
from e in db.Employees
join o in db.Books on e.EmployeeID equals o.EmployeeID into b
from x in b.DefaultIfEmpty()
select new
{
e.ID,
e.Name,
o.BookName
};

[rockmmm]

[Quote=引用 1 楼 wuyq11 的回复:]
LINQ使用JOIN
var q =
from e in db.Employees
join o in db.Books on e.EmployeeID equals o.EmployeeID into b
from x in b.DefaultIfEmpty()
select new
{
e.ID,
e.Name,
……
[/Quote]

不要这种写法的，用lambda表达式，像文中那样，请多帮忙。

[q107770540]

   var query8 = lp.SelectMany(r=>r.Cars,(r,c)=>new {Player = r,Car = c}).
            Join(mf,r1=>r1.Car,r2=>r2.Car,(r1,r2)=>new {Name = r1.Player.Name,Car = r1.Car,Fac = r2.Name==null?"":r2.Name}).
            GroupBy(r=>r.Name);

[rockmmm]

[Quote=引用 3 楼 q107770540 的回复:]
C# code

var query8 = lp.SelectMany(r=>r.Cars,(r,c)=>new {Player = r,Car = c}).
Join(mf,r1=>r1.Car,r2=>r2.Car,(r1,r2)=>new {Name = r1.Player.Name,Car = r1.Car,Fac = r2.Name==null?"":……
[/Quote]

结果上跟原来代码中是一样的，对于没有生产厂家的汽车，同样也是不显示的。
希望能再改改。

[q107770540]

注意使用DefaultIfEmpty()来实现

var query8 = lp.SelectMany(r=>r.Cars,(r,c)=>new {Player = r,Car = c}).
            Join(mf.DefaultIfEmpty,r1=>r1.Car,r2=>r2.Car,(r1,r2)=>new {Name = r1.Player.Name,Car = r1.Car,Fac = r2.Name==null?"":r2.Name).
            GroupBy(r=>r.Name);

[rockmmm]

[Quote=引用 6 楼 q107770540 的回复:]
注意使用DefaultIfEmpty()来实现

C# code


var query8 = lp.SelectMany(r=>r.Cars,(r,c)=>new {Player = r,Car = c}).
Join(mf.DefaultIfEmpty,r1=>r1.Car,r2=>r2.Car,(r1,r2)=>new {Name = r1.Player.……
[/Quote]
不好意思，我试了一下，老样子。兄弟你再想想。

[q107770540]

不要使用labda表达式
用查询语句
在查询语句中使用DefaultIfEmpty()

[rockmmm]

[Quote=引用 8 楼 q107770540 的回复:]
不要使用labda表达式
用查询语句
在查询语句中使用DefaultIfEmpty()
[/Quote]

是不是可以认为用lambda无法实现上述要求？

[rockmmm]

自已顶一下

[坚果o]

GroupJoin