I have problem with Executequery:
Error message: "Specified cast is not valid". I tried do:

```
var qq = db.ExecuteQuery<class_search>(query, ddl4, ddl5, ddl1).ToList();

```

But the same error too. I tried in few ways yet. Always is this error or "The query results cannot be enumerated more than once", when I tried do IEnumerable. I read many articles but I don't how do it. What am I doing incorrectly, or missing?

```
public class class_search
{
    public string path_image
    { get; set; }

    public string name_product
    { get; set; }

    public float cost
    { get; set; }
} 

public partial class Search : System.Web.UI.Page
{
    DataClasses1DataContext db = new DataClasses1DataContext();

    string ddl4 = DropDownList4.SelectedItem.Value;
    string ddl5 = DropDownList5.SelectedItem.Value;
    string ddl1 = DropDownList1.SelectedItem.Value;

    string query = "select p.path_image, p.name_product, p.cost from Table1 a, Table2  p, Table3 k where a.column1 = {0} and a.column2 = {1} and k.column2 = {2} and p.IDForeignColumn1 = k.IDcolumn and p.IDForeignColumn2 = a.IDcolumn"

    var qq = db.ExecuteQuery<class_search>(query, ddl4, ddl5, ddl1);

    ListView1.DataSource = qq;
    ListView1.DataBind();
}

```

//I changed code to eng language. Now a.column1, a.column2 and k.column2 are string types.