The type or namespace name 'OracleConnection' could not be found

Question

I am getting this error every time I try to debug my program:

CS0246: The type or namespace name 'OracleConnection' could not be found (are you missing a using directive or an assembly reference?)

This occurs on the declaration private readonly OracleConnection oracleConnection; (and in a few other places as well)

I have been trying a number of suggested solutions but so far none have worked:

• I have added a reference to the System.Data.OracleClient.dll
• My target framework is set to .NET Framework 4
• I have tried both including using System.Data.OracleClient and manually writing out System.Data.OracleClient.OracleConnection

EDIT: The code I am using is as follows:

using System;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using System.Collections.Generic;
using System.Data.OleDb;
using System.Linq;
using System.Web;
using System.Data;
using System.Configuration;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

namespace Foo
{
    public class DBHandler
    {
        private readonly OracleConnection oracleConnection;
        private readonly OracleCommand oracleCommand;
        private readonly OracleDataAdapter oracleAdapter;

Nothing has worked so far, so any suggestions would be appreciated.

Answer 1

I managed to solve this one, though I don't know how what I changed affected anything. The DBHandler.cs file was located in a folder called "App_Code". Moving the file up one level (into the main project folder) seems to have solved the error.

Answer 2

First of all, for Oracle, System.Data.OracleClient has been deprecated and therefore it's not been recommended now. For details, please visit ADO.NET Team Blog Post

What is recommended is Oracle client published by Oracle corporation. Download the Oracle Data Access component from Oracle .NET Developer Center

Then in the same way, you can use OracleConnection, OracleCommand etc. by adding reference to Oracle.Client dll.

Further please note this library wont be available for .NET 4 Client Profile.

Answer 3

I think the using directive got removed.

using System;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using System.Data.OracleClient; //Add This
using System.Collections.Generic;
using System.Data.OleDb;
using System.Linq;
using System.Web;
using System.Data;
using System.Configuration;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

namespace Foo {

public class DBHandler
    {

        private readonly OracleConnection oracleConnection;
        private readonly OracleCommand oracleCommand;
        private readonly OracleDataAdapter oracleAdapter;

Did you maybe try each of those steps individually and then set them back when they didn't work?

Answer 4

Project->Add reference->Oracle.DataAccess
Here there are two versions- 2.something and 4.something. When I selected the version 4 it did't resolve the namespace, but when I selected the version 2 it resolved!!