Oracle Database Connection

I'm beginner about web programming and I have a problem with oracle db connection. My code is working well with Mssql but it's not working with oracle. I want to change db to oracle from mssql. I have downloaded odac. Here is my SqlOperations class.

using System;
using System.Collections.Generic;
using System.Data;
using Oracle.DataAccess;
using System.Data.OracleClient;
using System.Data.Odbc;
using System.Linq;
using System.Web;

namespace BagciEmlak
{
public class SqlOperations
{
    OracleConnection con;
    OracleCommand cmd;
    OracleDataAdapter sda;
    DataTable dt;
    public OracleConnection OracleConnect()
    {
        try
        {
            con = new OracleConnection ("Data Source=SYS-CDB12c; User ID=HR; Password=hr; Unicode=true;");
            con.Open();
            return con;
        }
        catch (OracleException e)
        {

            throw;
        }

    }
    public int Command(string ConStr, OracleConnection conn)
    {
        try
        {
            cmd = new OracleCommand(ConStr, conn);

            return cmd.ExecuteNonQuery();
        }
        catch (Exception e)
        {

            throw;
        }
        finally
        {
            cmd.Dispose();
            conn.Close();
            conn.Dispose();
        }


    }
    public DataTable GetDataTable(string ConStr, OracleConnection conn)
    {
        try
        {
            dt = new DataTable();
            sda = new OracleDataAdapter(ConStr, conn);
            sda.Fill(dt);

            return dt;
        }
        catch (Exception e)
        {

            throw;
        }
        finally
        {
            sda.Dispose();
            conn.Close();
            conn.Dispose();
        }

    }
    public DataRow GetDataRow(string ConStr, OracleConnection conn)
    {
        dt = GetDataTable(ConStr, conn);
        if (dt.Rows.Count==0)
        {
            return null;
        }
        else
        {
            return dt.Rows[0];
        }
    }
    public string GetDataCell(string ConStr, OracleConnection conn)
    {
        dt = GetDataTable(ConStr, conn);
        if (dt.Rows.Count == 0)
        {
            return null;
        }
        else
        {
            return dt.Rows[0][0].ToString();
        }
    }

}

}

and here is my webconfig code:

<connectionStrings>
    <add name="{ConnectionName}" 
    connectionString="Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=MyHost)(PORT=MyPort)))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=MyOracleSID)));User Id=HR;Password=HR;" 
    providerName="Oracle.DataAccess.Client"/>
 </connectionStrings>

So whats wrong within can you help me