Question

OS: Windows 7 64bit
VB: Visual Studio 2010
Oracle Client: 11g

I am developing an application that connects to an Oracle 11g server. I am able to connect to the Oracle server via Oracle SQL Developer, ODBC (in SYSWOW64), and in VB Server Explorer.

I am using the .NET reference Oracle.DataAccess located at: C:\Oracle\product\11.2.0\client_32\ODP.NET\bin\2.x\Oracle.DataAccess.dll

I have tried adding the .DLL files to my bin folder as suggested by other questions and that does not work.

Does anyone have any other suggestions?

When I run my application, I get the following:

Here are the details:

System.TypeInitializationException was unhandled
  Message=The type initializer for 'Oracle.DataAccess.Client.OracleConnection' threw an exception.
  Source=Oracle.DataAccess
  TypeName=Oracle.DataAccess.Client.OracleConnection
  StackTrace:
       at Oracle.DataAccess.Client.OracleConnection..ctor(String connectionString)
       at Orc_Test_1.Form1.Button1_Click(Object sender, EventArgs e) in c:\Visual Studio 2010\Projects\Orc_Test_1\Orc_Test_1\Form1.vb:line 9
       at System.Windows.Forms.Control.OnClick(EventArgs e)
       at System.Windows.Forms.Button.OnClick(EventArgs e)
       at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
       at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.ButtonBase.WndProc(Message& m)
       at System.Windows.Forms.Button.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
       at Orc_Test_1.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: Oracle.DataAccess.Client.OracleException
       DataSource=""
       ErrorCode=-2147467259
       Message=The provider is not compatible with the version of Oracle client
       Number=-11
       Procedure=""
       Source=Oracle Data Provider for .NET
       StackTrace:
            at Oracle.DataAccess.Client.OracleInit.Initialize()
            at Oracle.DataAccess.Client.OracleConnection..cctor()
       InnerException: 

VB.NET Code:

Imports System.Data
Imports Oracle.DataAccess.Client ' ODP.NET Oracle managed provider
Imports Oracle.DataAccess.Types

Public Class Form1

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim oradb As String = "Data Source=SERVER1;Persist Security Info=True;User ID=username;Password=password;Unicode=True" 'From Server Explorer
        'Dim oradb As String = "Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=Server1.host.net)(PORT=1522))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=Server1))); USER ID = username;Password = password;" 'From TNSnames.ora
        Dim conn As New OracleConnection(oradb)  '<--- Error happens on this line
        conn.Open()
        Dim cmd As New OracleCommand
        cmd.Connection = conn
        cmd.CommandText = "select system_id from schema1.system_impacted where system_name = AWESOME"
        cmd.CommandType = CommandType.Text
        Dim dr As OracleDataReader = cmd.ExecuteReader()
        dr.Read()
        Label1.Text = dr.Item("system_id")
        conn.Dispose()
    End Sub
End Class

Answer 1

I removed all of the oracle clients that were available in the ‘Programs’ section of ‘Control Panel’. Then I went into the registry searched for ‘Oracle’ and removed all instances/references of Oracle client(s). After 3 hours of registry removal and a reboot, I installed the 11g client and everything worked as expected.

Note: when searching the registry for “Oracle”, there may be references to the VB version of Oracle, or a reference to Crytsal Reports driver for ‘Oracle’. I did not remove these. So pay attention to the file location and/or the syntax of the registry item you are deleting.

/Reading. It works.