You can use a connection string similar to this:
The select statements should look like this:
SELECT * FROM listName
You can use the Item-IDs as primary keys for updating.
How to get the SharePoint list guid in browser?
Go to the list settings page. Right click on "Title, description and navigation" and copy the URL. Paste that into notepad and copy everything after "List=" in the string. That's your URL Encoded GUID for the list. All you need to do is decode it.
How to decode the SharePoint List guid (and any other encoded URL)?
You can use this page to decode encoded URLs: