Note: For the purposes of this post I’m going to assume you know the difference between the display name and the internal name of a field and why you should use the internal name when referring to fields in code and queries.
There are several tools/tricks you can use to get the internal name of a field. In this quick tip I’ll show you two tools I like to use: Visual Studio and SharePoint Manager.
Let’s say we have a site named Demo that contains a list named Demo that contains a field named Application Type and that I want to get the internal name of this field. I can open Server Explorer in Visual Studio 2010, expand SharePoint Connections, expand the appropriate site collection (you’ll need to attach to it if there is no node), expand the Demo site, expand Lists and Libraries, expand Lists, expand Demo, expand Fields, and finally select Application Type. With this node selected I can look at the properties of the field in the Properties Window, one of these will be the internal name.
Now, let’s say we want to get the internal name of the % Complete site column in the Demo site. The Server Explorer does not contain a node for site columns so we’ll use SharePoint Manager 2010 instead. SharePoint Manager is a free tool you can download from http://spm.codeplex.com/. Once you’ve downloaded the 2010 version and unzipped (there’s no install necessary), run the program as administrator. Just like we did in the Server Explorer, navigate down the tree view until you can select the node representing the % Complete field. The window on the right will show its properties, including the internal name.