Best Overloaded method match has some invalid arguments - asp.net-mvc

Question

I have two tables deal_outlet and vendors_outlet. I am trying to compare a list of outlet_id from deal_outlet table to vendor table but .contain method shows error has some invalid arguments. I really don't understand problem in this code.
public ActionResult Detail_of_deal(int id)
{
var d1 = db.deal_outlet.Where(x => x.outlet_id==id).ToList();
f_model.model4 = db.vendors_outlet.Where(x =>d1.Contains(x.outlet_id)).ToList();
var d = obj.detail_of_image(id,ref model);
return View(f_model);
}

Answer 1

Depending on the goal of the code you could try the following:
public ActionResult Detail_of_deal(int id)
{
var d1 = db.deal_outlet.Where(x => x.outlet_id==id).ToList();
f_model.model4 = db.vendors_outlet.AsEnumerable().Select(x => d1.Contains(x.outlet_id)).ToList();
var d = obj.detail_of_image(id,ref model);
return View(f_model);
}
That should make f_model.model4 a list of all the vendors_outlets that have a matching deal_outlet.id

Answer 2

The Linq Contains method returns true if the list contains the item passed in. You are asking to see if a list of deal_outlet objects contains an int, which obviously it won't.
Instead of projecting a collection of deal_outlets, project a list of integers:
var d1 = db.deal_outlet.Where(x => x.outlet_id==id).Select(x => x.outlet_id);
f_model.model4 = db.vendors_outlet.Where(x =>d1.Contains(x.outlet_id)).ToList();
But logically, that's the same as:
f_model.model4 = db.vendors_outlet.Where(x =>x.outlet_i==id)).ToList();
So it's not clear what you're trying to do.
EDIT
Based on your comments, I believe these are the queries you want:
i am trying to fetch list of outlet_id from deal_outlet table where deal_id equal to id,
var d1 = db.deal_outlet.Where(x => x.deal_id==id).ToList();
Now want to compare this list to vendor_outlet table and fetch those rows where outlet_id from deal_outlet table equals to outlet_id in vendor_outlet table
Get a list of ID's to match:
var ids = d1.Select(x => x.outlet_id).ToList();
And use Contains to see if the list contains any of the IDs from the related table:
f_model.model4 = db.vendors_outlet.Where(vo => ids.Contains(vo.outlet_id))
.ToList();