title: jOOQ - nested object with many to many relationship
body: <p>I've been trying to figure out how to convert nested objects from a jOOQ query.
  I've seen the RecordMapper or java 8 streams mentioned as possible solutions but have trouble figuring out how I could use those.</p>
  <p>My objects look similar to this, with Student-Teacher being a N:N relationship and Student-Book a 1:N.</p>
  <pre><code>Student {
    List&lt;Teacher&gt; teachers
    List&lt;Book&gt; books;
  }
  </code></pre>
  <p>Now I want to query the tables using jooq and convert that to a Student object that contains the others. Is there a straight forward way to do this? Are there examples that show how to achieve this?
  Is intoGroups usable with a schema similar to this? If I do intoGroups do I get a list of all the different types of records that I joined the database with?</p>
  <p>I could also do 2 queries, that shouldn't really be a problem.
  Thanks.</p>