提示指定的转换无效。。。
class Northwind : DataContext
{
public Table<Depart> T_Dept;
public Northwind(string conn) : base(conn) { }
}
[Table(Name="T_Depart")]
public class Depart
{
[Column(IsPrimaryKey = true, IsDbGenerated = true)]
public int DeptId { set; get; }

[Column(Name="DeptManId")]
public int DeptManId { set; get; }
[Column]
public string DeptName { set; get; }
[Column]
public string DeptTel { set; get; }
[Column]
public string DeptFax { set; get; }

//public Table<Employee> emps { set; get; }
}
static void Main(string[] args)
{
Northwind nw = new Northwind(@"*****");
var select = (from td in nw.T_Dept
where td.DeptId == 1
select new
{
DeptId = td.DeptId,
DeptFax = td.DeptFax,
DeptTel = td.DeptTel,
DeptName = td.DeptName,
DeptManId = td.DeptManId
});
Depart dept = nw.T_Dept.First();
Console.ReadKey();
}


Depart dept = nw.T_Dept.First();提示指定的转换无效。。。
请问怎么解决？？？？

[解决办法]

C# code

Northwind nw = new Northwind(@"*****");  var select = (from td in nw.T_Dept  where td.DeptId == 1  select new Depart  //注意此处  {  DeptId = td.DeptId,  DeptFax = td.DeptFax,  DeptTel = td.DeptTel,  DeptName = td.DeptName,  DeptManId = td.DeptManId  }).FirstOrDefault();  Depart dept = (select ==null? new Depart(): select);  Console.ReadKey();
[解决办法]
http://www.cnblogs.com/JeffreyZhao/archive/2008/02/19/using-translate-method-and-modify-command-text-before-query-in-linq-to-sql.html

C# code
Northwind nw = new Northwind(@"*****");  var select = (from td in nw.T_Dept  where td.DeptId == 1  select new    {  DeptId = td.DeptId,  DeptFax = td.DeptFax,  DeptTel = td.DeptTel,  DeptName = td.DeptName,  DeptManId = td.DeptManId  }).FirstOrDefault(); using (dataContext.Connection)    {         Depart dept =nw.ExecuteQuery<Depart>(query, true).FirstOrDefault();    }
[解决办法]
探讨

    class Northwind : DataContext
    {
        public Table<Depart> T_Dept;
        public Northwind(string conn) : base(conn) { }
    }
    [Table(Name="T_Depart")]
    public class Depart
  ……