Invalid Cast AsEnumberable()

Question

using System;
using System.Data;
using System.Data.SqlClient;

namespace ConsAppAutoGenSql
{
    class Program
    {
        static void Main(string[] args)
        {
            SqlConnection conn = new SqlConnection(@"Data Source=localhost\sqlexpress;Initial Catalog=Northwind;Integrated Security=True");

            SqlCommand command = new SqlCommand("sp_sproc_columns", conn);
            command.CommandType = CommandType.StoredProcedure;

            SqlParameter prmSprocName = new SqlParameter("@procedure_name",SqlDbType.NVarChar, 384);
            Console.WriteLine("enter name of sproc");
            prmSprocName.Value = Console.ReadLine();

            command.Parameters.Add(prmSprocName);

            SqlDataAdapter da = new SqlDataAdapter(command);
            DataTable dt = new DataTable();

            try 
	        {	        
		        conn.Open();

                da.Fill(dt);

                var x = from myRow in dt.AsEnumerable()
                        where myRow.Field<int>("COLUMN_TYPE") == 1
                        select myRow;
                
                foreach (DataRow aRow in x)
                {                    
                    Console.WriteLine(aRow.Field<string>("COLUMN_NAME"));
                }

                Console.ReadLine();
	        }
	        catch (Exception ex)
	        {
                throw ex;
	        }
            finally
            {
                conn.Close();
            }
                       
        }
    }
}

I am getting the following runtime exception;

System.InvalidCastException was caught
  Message=Specified cast is not valid.
  Source=System.Data.DataSetExtensions
  StackTrace:
       at System.Data.DataRowExtensions.UnboxT`1.ValueField(Object value)
       at System.Data.DataRowExtensions.Field[T](DataRow row, String columnName)
       at ConsAppAutoGenSql.Program.<Main>b__0(DataRow myRow) in C:\Users\xxx\Documents\Visual Studio 2010\Projects\ConsoleApps\ConsAppAutoGenSql\ConsAppAutoGenSql\Program.cs:line 32
       at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()
       at ConsAppAutoGenSql.Program.Main(String[] args) in C:\Users\xxx\Documents\Visual Studio 2010\Projects\ConsoleApps\ConsAppAutoGenSql\ConsAppAutoGenSql\Program.cs:line 35
  InnerException: 

Can someone help, please?

---

UML, then code

Answer 1

Hi Berlioz99,

Welcome!

Please check the type of column "COLUMN_TYPE" to see whether it is "int". Your query and Loop look right.

Have a nice day.

---

Alan Chen[MSFT]
MSDN Community Support | Feedback to us
Get or Request Code Sample from Microsoft
Please remember to mark the replies as answers if they help and unmark them if they provide no help.

Answer 2

Hi,

I am writing to check the status of the issue on your side. Would you mind letting us know the result of the suggestions?

Have a nice day.

---

Alan Chen[MSFT]
MSDN Community Support | Feedback to us
Get or Request Code Sample from Microsoft
Please remember to mark the replies as answers if they help and unmark them if they provide no help.

Answer 3

Hello,

I agree with Alan please check the data type of the field "COLUMN_TYPE" I think there some issue there.

Answer 4

Yes, the column data type was incorrect...Thank you

---

UML, then code