foreach(var r in q)
{
    Console.WriteLine(r.CustomerId);
}

------解决方案--------------------
var q = from c in dc.Customers select c.CustomerId;

------解决方案--------------------
咋不结贴呢，2楼的方法不行？

------解决方案--------------------
C# code


                var q = from c in db.Customers
                        select c.CustomerID;
                foreach (var id in q)
                {

                    Response.Write(id + ",");
                }

------解决方案--------------------
假设CustomerId的类型是long，可以写：

var q = from c in dc.Customers select c;  
var r= from Customer c in q select c.id;  //取出每行CustomerId的值