visual studio 2008 - The provider is not compatible with the version of Oracle client error when using Oracle.DataClient

Question

I'm using Visual Studio 2008 Express Edition, and I'm trying my hand in developing a small application using Oracle.DataClient. I'm getting the above mentioned error, when trying to connect to the database in the target system.

I've added a reference to Oracle ODP.net provider for Oracle 10gR2, and in the target machine I have a copy of Oracle 10gR2 database installed. Despite this, I'm getting the error. Before posting this, I read this post at SO, and I have installed the instant client, the error persists. Below is the full error stack.

************** Exception Text **************
System.TypeInitializationException: The type initializer for 'Oracle.DataAccess.Client.OracleConnection' threw an exception. ---> Oracle.DataAccess.Client.OracleException The provider is not compatible with the version of Oracle client    at Oracle.DataAccess.Client.OracleInit.Initialize()
   at Oracle.DataAccess.Client.OracleConnection..cctor()
   --- End of inner exception stack trace ---
   at Oracle.DataAccess.Client.OracleConnection..ctor(String connectionString)
   at Employees1.frmLogin.oralogin()
   at Employees1.frmLogin.btnTest_Click(Object sender, EventArgs e)
   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.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


************** Loaded Assemblies **************
mscorlib
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.42 (RTM.050727-4200)
    CodeBase: file:///C:/WINDOWS/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll
----------------------------------------
API Data Conversion Assistant
    Assembly Version: 0.0.0.1
    Win32 Version: 0.0.0.1
    CodeBase: file:///C:/Documents%20and%20Settings/3i/My%20Documents/My%20Dropbox/Sathya's%20dropbox/VisualStudio%20Releases/APIDataconversion/Application%20Files/API%20Data%20Conversion%20Assistant_0_0_0_3/API%20Data%20Conversion%20Assistant.exe
----------------------------------------
System.Windows.Forms
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.42 (RTM.050727-4200)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.42 (RTM.050727-4200)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Drawing
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.42 (RTM.050727-4200)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
Oracle.DataAccess
    Assembly Version: 2.102.2.20
    Win32 Version: 2.102.2.20

I have Oracle 11g installed on the machine on which I developed the application, and it works fine there, but on the target machine, I'm getting this error. Any inputs will be appreciated.

PS: As mentioned above, the referenced Oracle.DataClient.dll file version corresponds to 10gR2, not 11g.

Answer 1

I've been looking into this problem further, and you simply need to grab all the appropriate DLL's from the same downloaded version of ODP.Net and put them in the same folder as your Exe file, because ODP.Net is fussy about not mixing version numbers, which is the problem you're seeing (either that or the oci.dll is totally missing, in which case it annoyingly gives the same error).

I've explained how to do this here: http://splinter.com.au/using-the-new-odpnet-to-access-oracle-from-c Here's the gist of it though:

• Download http://www.oracle.com/technology/software/tech/windows/odpnet/index1110710beta.html
• Unzip the file
• Unzip all the JAR's in it
• Grab these dll's that were just unzipped: oci.dll (renamed from 'oci.dll.dbl') Oracle.DataAccess.dll oraociicus11.dll OraOps11w.dll orannzsbb11.dll oraocci11.dll ociw32.dll (renamed from 'ociw32.dll.dbl')
• Put all the DLLs in the same folder as your C# Executable