title: Which type/class should I use to map different values?
body: <p>I have a backend table as shown below and I am reading it using ado.net.</p>
  
  <p>I tried to convert this to a dictionary with key value pair, but I don't know how to map keys and values so that when I read <code>code 1</code> I can return its category name, and when I read 2 as <code>code 3</code> as subcode I can read both its corresponding category and subcategory?(Say ex., Old, ThreeMonth).</p>
  
  <p>Is there any other type/class available to acheive this functionality?</p>
  
  <pre><code>code    Sub_Code    Category    Sub_Category
  1             1     NEW                  NEW
  2             1         Old             OneMonth
  2             2         Old                 TwoMonth
  2             3         Old                 ThreeMonth
  2             4         Old                 Ninemonth
  5             4     APPOINTMENT         APPOINTMENT MADE
  9             4         Invalid             LANGUAGE BARRIER
  </code></pre>