Question

I have code like this

var db = new BigDataEntities(); 
var g = db.Tab1
           .GroupJoin(db.Tab1, a => a.id, b => b.id, (a, b) => new {a, b})
           .GroupJoin(db.Tab1, c => c.a.id, d => d.id, (c, d) => new {c, d})
           .Select(t => t.c.b.id);

I’m not sure why I use t.c.a.id works well, but t.c.b.id can’t work, I can’t get ‘id’ from t.c.b; If I use Join instead of GroupJoin, everything works well. Anyone can help?

Answer 1

That is because t.c.b is an IEnumerable<b>. When you use Join, new {a, b} is an IEnumerable of an anonymous type having properties a and b.