There is no need a separate DNS creation for connection Oracle with the dotnet application like Java.
We can directly connect the Oracle with our dotnet application using the wizard of connection like ODBC.
You can do the following steps:
1. From Project menu, select Add Reference...
2. Scroll down the list of Component Names and select Oracle.DataAccess. Click OK.
Now while coding, add the reference
using Oracle.DataAccess.Client; // ODP.NET Oracle managed provider