title: Update multiple rows with different values
body: <p>I have these 3 tables</p>
  
  <p>Table books (i want to fill categories column with 1 string of categories delimited with a comma)</p>
  
  <pre><code>id      categories
  1       null
  2       null
  3       null
  ...     ...
  </code></pre>
  
  <p>Table categories</p>
  
  <pre><code>id      name
  1       adventure
  2       horror
  ...     ...
  </code></pre>
  
  <p>Table BooksCategories (a book can have multiple categories)</p>
  
  <pre><code>bookid    categoryid
  1         1
  1         3
  2         2
  3         1
  3         2
  ...       ...  
  </code></pre>
  
  <p>I have a query that gives me something like this</p>
  
  <pre><code>bookid      categories
  1           horror, adventure
  2           action,...,...
  </code></pre>
  
  <p>Now, I want to update the column categories of my books table to the corresponding value of my query. Is it possible to do that in an update?</p>
  
  <p>Thanks, I hope it is clear enough</p>