linq join 多条件查询

var test2=from n in a
              join n1 in b on new {id1=n.id,id2='abc'} equals new {n1.id1,n2.id2}  select n;

 

var test1=from n in a
              join n1 in b on new {id1=n.id,id2=n.id2} equals new {n1.id1,n2.id2}  select n;