 <p>The connections strings that I use look like</p> <pre><code>&lt;add name="myOracleConnection" connectionString="Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=MyServer)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=XE))); User Id=MyUser; Password=MyPassword;" providerName="system.data.oracleclient"/&gt; </code></pre> <p>I.e. I do not rely on these external configuration files (were they named <code>.ora</code>? I forgot it).</p> <p>Maybe you can lower dependencies and side-effects if you also try to make your connection string self-containing with <em>everything</em> included?</p>