title: Update database record grails
body: <p>For example I've been written a simple domain-class:</p>
  
  <pre><code>class Book{
    String bookName
  }
  </code></pre>
  
  <p>I've done some records of this instance. And now I wanna update one of them, to realize it, I've an idea to write a setter for <code>bookName</code>. But may be is more elegant method to do this via GORM-methods? </p>