title: Where (how) to store categories (sort of) tree in my database?
body: <p>So, I am modeling a database using MySQL Workbench. I have a table called Category (two fields, id and description) and a table called Event. I would like to have a column in Event that holds any number of ids from Categories (as CSV, and their order is important).
  How do I represent this in MySQL Workbench (in a ER model, I mean)? Or I am doing this really wrong?</p>
  
  <p>It'll look something like this:</p>
  
  <pre><code>| ID | Descripion
  |  1 | Lorem...
  |  2 | Ipsum...
  |  3 | Dolor...
  |  4 | Sit...
  |  5 | Amet...
  
  
  | ID | Name   | Categories
  |  1 | John   | 2,1,5,4
  |  2 | Reese  | 3,5,4
  |  3 | Ben    | 1,5
  |  4 | Linus  | 3,4,2
  |  5 | Jack   | 5
  |  6 | Lemon  | 4,5,2
  </code></pre>
  
  <p>(I've already read this: <a href="https://stackoverflow.com/questions/7941228/how-to-structure-categories-data-in-the-database">How to structure &quot;categories&quot; data in the database?</a> but I am not sure I am in the same situation. My categories are more like a 'tree' than tags...)</p>