How to do joins in LINQ on multiple fields in single join
var result = from x in entity
join y in entity2 on new { x.field1, x.field2 } equals new { y.field1, y.field2 }
var result = from x in entity1
join y in entity2
on new { X1= x.field1, X2= x.field2 } equals new { X1=y.field1, X2= y.field2 }
You need to do this, if the column names are different in two entities.