在LINQ加盟两套(joining two sets in LINQ)

    var setsA = new List<SetA> {
        new SetA { SsnA = "3450734507", name = "setA"},
        new SetA { SsnA = "6833467788", name = "setA"},
        new SetA { SsnA = "5452347787", name = "setA"},
        new SetA { SsnA = "9345345345", name = "setA"},
    };

    var setsB = new List<SetB> {
        new SetB { SsnB = "5452347787" ,name = "setB"},
        new SetB { SsnB = "9345345345", name = "setB"},
    };

当我使用这个LINQ：

var Set =
                from seta in setsA
                join setb in setsB
                 on seta.SsnA
                    equals setb.SsnB
                select new { 
                    SSN = seta.SsnA,
                    NAME = setb.name
                };

我得到这个值：

{ SSN = "5452347787", NAME = "setB" }
{ SSN = "9345345345", NAME = "setB" }

但我希望有一套结合了这两个结果将是：

{ SSN = "3450734507", NAME = "setA" }
{ SSN = "6833467788", NAME = "setA" }
{ SSN = "5452347787", NAME = "setB" }
{ SSN = "9345345345", NAME = "setB" }

这将是一个结果集，会告诉我与设置是从拍摄，如果SSN在组A和组B那就财产NAME =“组B”中找到的名称name属性

可能有人帮助我？

Answer 1:

看来你想要一个外连接 - 这是使用群组加入做：

var set = setsA.GroupJoin(
    setsB,
    sa => sa.SsnA,
    sb => sb.SsnB,
    (a, bs) => new { SSN = a.SsnA, NAME = bs.Any() ? "setB" : "setA" });

Answer 2:

这里所描述的LINQ方式： http://msdn.microsoft.com/en-us/library/bb397895.aspx是这样的（功能相同的拉姆达方式）：

 var set = from a in setsA
           join b in setsB on a.SsnA equals b.SsnB into g
           from o in g.DefaultIfEmpty()
           select new { SSN = a.SsnA, NAME = (o != null ? o.name : a.name)};

文章来源: joining two sets in LINQ