Accessing Oracle from .NET
September 5, 2008
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I am a MS guy & prefer to work & express myself using MS technologies. Lately things changed. I had to work on a product that supported Oracle DB. It has been a long time since I had written code to connect to Oracle DB, less even to install an Oracle Database. Luckily for me Oracle DB was already installed. So I set out to connect to Oracle. I found that there are quite a few options to connect to Oracle. I am going to discuss them in this post.
1) You can do it via Microsoft .NET data provider for ODBC / OLEDB. This look like old way of communication to me especially when ADO.NET provides the powerful data provider model.
2) Microsoft’s data provider for Oracle – This is installed by default while installing .NET Framework / VS.NET. The provider resides in System.Data.OracleClient assembly. This requires the installation of Oracle client software.
(N.B. If you are using .NET 1.0 / VS.NET 2002 you can download the provider here. Oracle Client software seems to be specific to version of Oracle, for instance you can get access to 10g client from here & 9i Client from here. I haven’t tried the backward compatibility for the Oracle Client Software i.e. accessing 9i database from 10g client).
3) Oracle Data Provider for .NET (ODP.NET) is the ADO.NET provider coming straight from Oracle. It seems to be better in Performance & more close to Oracle in terms of available features. You can download the same here. Note this bundle also includes ASP.NET Provider, Oracle Services for Distributed Transactions, support for .NET 2.0 & 1.x. I tried installing Oracle 11g ODAC, it works perfectly fine with VS.NET 2008 & I was able to connect to my 9i Oracle instance from it. Oracle also provides Developer Tools for Visual Studio (ODT.NET), which for instance allows you to access Oracle from server explorer. A detail list of ODT features can be found here. ODT also comes bundled with ODP, & the same can be downloaded from here. The base assembly for ODP.NET is Oracle.DataAccess.
(N.B. After installation you of Oracle Client / ODP you need to create a file named TNSNAMES.ORA in the %Oracle Installation%/Network/Admin folder).
4) Of course I didn’t use either of above. We are using a O/R mapper & one which seems to be reasonable at present is NHibernate. You can download its latest version 2.0 from here. NHibernate 2.0 wiki is here. Now the question is how to you make NHibernate use ODP.NET? Simplest solution is given here.
Hope this would save your valuable time.