I download the Oracle client was downloaded from https://www.oracle.com/database/technologies/oracle19c-windows-downloads.html and select the file "NT_193000_client.zip" under the heading "Oracle Database 19c Client (19.3) for Microsoft Windows (32-bit)".
I then installed it on my server. When I run a TNSPing command to check the version number and bit-ness of the Oracle Client installed, I get:
TNS Ping Utility for 32-bit Windows: Version 19.0.0.0.0 - Production on 20-OCT-2022 22:50:49
I then used SQLPlus to verify that I could connect to the database.
Next, I compiled the following simple C# program that tests Oracle connectivity. The program was compiled as a 32-bit .NET 6 program.
using System;
namespace TestOracle
{
internal class Program
{
static void Main(string[] args)
{
string cs = "Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=servernm.sys.myco.com)(PORT=1521)))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=MySERVICE.MYCO.com)));User Id=MYID;Password=MYPWD;Validate Connection=True;";
try
{
int count = Db.TestConnectivity(cs);
Console.WriteLine($"Count={count}");
}
catch (Exception e)
{
Console.WriteLine(e);
}
var key = Console.ReadKey();
}
}
}
using Oracle.DataAccess.Client;
using System;
using System.Data;
using System.Text;
namespace TestOracle
{
public static class Db
{
public static int TestConnectivity(string connectionString)
{
var sqlStringBuilder = new StringBuilder();
sqlStringBuilder.AppendLine($"SELECT 1 AS RecordCount FROM DUAL");
using (OracleConnection connection = new OracleConnection(connectionString))
{
connection.Open();
OracleCommand command = connection.CreateCommand();
command.Connection = connection;
var oleDbDataAdapter = new OracleDataAdapter(command);
command.CommandText = sqlStringBuilder.ToString();
DataSet dataset = new DataSet();
oleDbDataAdapter.Fill(dataset);
return Convert.ToInt32(dataset.Tables[0].Rows[0]["RecordCount"]);
}
}
}
}
When I ran the program, I get this error:
System.IO.FileNotFoundException: Could not load file or assembly 'Oracle.DataAccess, Version=2.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342' or one of its dependencies. The system cannot find the file specified.
File name: 'Oracle.DataAccess, Version=2.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342'
at TestOracle.Db.TestConnectivity(String connectionString)
at TestOracle.Program.Main(String[] args) in C:\Users\C39293\OneDrive - CIGNA\Documents\Visual Studio 2015\Projects\Dokmanovich.File2Table\TestOracle\Program.cs:line 13
WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].
I know that this is a common error and that the common issue is a mismatch of bitness or a version problem. In my case, the bitness of my program, 32, matches the bitness of the client installed. Furthermore, I expect that if the program runs on my machine with an Oracle client of 12.1, that a higher level client, 19, should also work. Is this assumption true? I was unable to find the exact same oracle Client.
What am I missing?
Update
When I looked in my C# project References, I saw that the Oracle.DataAccess.dll pointed to my 64 Oracle client folder on my machine, not my 32 bit one ( I have both clients). Since I want to run on a server that only has the 32 bit Oracle client, I changed the reference to point to the 32 bit dll and re-compiled it as before, as a 32 bit program.
When I reran the program on the server, I got a different error:
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 TestOracle.Db.TestConnectivity(String connectionString) in C:\Users\Myid\OneDrive - CIGNA\Documents\Visual Studio 2015\Projects\MyName.File2Table\TestOracle\Db.cs:line 15
at TestOracle.Program.Main(String[] args) in C:\Users\MyId\OneDrive - CIGNA\Documents\Visual Studio 2015\Projects\MyName.File2Table\TestOracle\Program.cs:line 13
I guess this is suggesting that I have the wrong Client. What should I have installed so this code runs on the server?
Update 2
I had two version of the 32 Oracle.DataAccess.dll, version 2.121.20 and 4.121.2.0. The error was the same for both (the error message immediately above).
