title: How to normalise my data
body: <p>First post i have been lurking for many years but finally stumped enough to ask for help? Please excuse the formatting</p>
  
  <p>I have generated a mind map (categories, subcategories, questions and responses) Im trying to find a data structure to map this. Once I map the data I end up with lots of repetition where a question and its children fit under multiple categories and subcategories. This leads me to believe my structure is poor and this can be normalised in some way which is eluding me.</p>
  
  <p>E.g. <strong>Thinking of shopping and advertising, which of the following have you ever done?</strong> </p>
  
  <ul>
  <li>(cat_id = 1) SHOPPING &amp; ADVERTISING (parent Category)
  
  <ul>
  <li>(cat_id = 41) Shopping information/Purchases (Sub category)
  
  <ul>
  <li>(ID- 1234) Thinking of shopping and advertising, which of the following have you ever done? 
  
  <ul>
  <li>(ID- 4111) How often do you do this via your TV screen?</li>
  <li>(ID- 4112) How often do you do this via your desktop computer?</li>
  <li>(ID- 4113) How often do you do this via your laptop computer?</li>
  </ul></li>
  </ul></li>
  </ul></li>
  <li><p>(cat_id = 1) SHOPPING &amp; ADVERTISING (parent Category)</p>
  
  <ul>
  <li>(cat_id = 44) No split - shopping and advertising (Sub category)
  
  <ul>
  <li>(ID- 1234) Thinking of shopping and advertising, which of the following have you ever done? 
  
  <ul>
  <li>(ID- 4111) How often do you do this via your TV screen?</li>
  <li>(ID- 4112) How often do you do this via your desktop computer?</li>
  <li>(ID- 4113) How often do you do this via your laptop computer?</li>
  </ul></li>
  </ul></li>
  </ul></li>
  <li><p>(cat_id = 2) SCREENS &amp; DEVICES (parent Category)</p>
  
  <ul>
  <li>(cat_id = 51)Usage/Shared usage (Sub category)
  
  <ul>
  <li>(ID- 1234) Thinking of shopping and advertising, which of the following have you ever done? 
  
  <ul>
  <li>(ID- 4111) How often do you do this via your TV screen?</li>
  <li>(ID- 4112) How often do you do this via your desktop computer?</li>
  <li>(ID- 4113) How often do you do this via your laptop computer?</li>
  </ul></li>
  </ul></li>
  </ul></li>
  <li>(cat_id = 2) SCREENS &amp; DEVICES (parent Category)
  
  <ul>
  <li>(cat_id = 52)TV (Sub category)
  
  <ul>
  <li>(ID- 1234) Thinking of shopping and advertising, which of the following have you ever done? 
  
  <ul>
  <li>(ID- 4111) How often do you do this via your TV screen?</li>
  </ul></li>
  </ul></li>
  </ul></li>
  </ul>
  
  <p>So in order to map this i created the following table. Please note I already have a Question table and a category table that link to this, that contains the IDs above.</p>
  
  <pre><code>| id    | object_id     | parent_id     | type  |  
  |----   |-----------    |-----------    |------ |  
  | 1     | 1             | NULL          | 1     |  
  | 2     | 41            | 1             | 1     |  
  | 3     | 1234          | 41            | 2     |  
  | 4     | 4111          | 1234          | 2     |  
  | 5     | 4112          | 1234          | 2     |  
  | 6     | 4113          | 1234          | 2     |  
  | 7     | 44            | 1             | 1     |  
  | 8     | 1234          | 44            | 2     |  
  | 9     | 4111          | 1234          | 2     |  
  | 10    | 4112          | 1234          | 2     |  
  | 11    | 4113          | 1234          | 2     |  
  | 12    | 2             | NULL          | 1     |  
  | 13    | 51            | 2             | 1     |  
  | 14    | 1234          | 51            | 2     |  
  | 15    | 4111          | 1234          | 2     |  
  | 16    | 4112          | 1234          | 2     |  
  | 17    | 4113          | 1234          | 2     |  
  | 18    | 52            | 2             | 1     |  
  | 19    | 1234          | 52            | 2     |  
  | 20    | 4111          | 1234          | 2     |  
  | 21    | 4112          | 1234          | 2     |  
  | 22    | 4113          | 1234          | 2     |  
  </code></pre>
  
  <p>As you can see above there is a lot of repetition. Other than the ID given for the table 4,5,6,9,10,11,15,16,17,20,21,22 is the same data. which makes me think this isn't the most efficient way if approaching this. I have a feeling I should be splitting this out by object ID and then having all parent but then I start to lose track and get lost. This is a small sample the above example is repeated a lot of times in the mind map as i can be access through multiple paths</p>
  
  <p>Can anyone help? Is it possible or is what I have done sufficient.</p>