title: Why is GORM performing cascading delete, even if I omit the belongsTo keyword?
body: <p>I have the following domain classes: </p>
  
  <p><strong>Holiday</strong>:</p>
  
  <pre><code>class Holiday {
      String justification
      User user
      //static belongsTo = User
          static constraints = {
          }
  }
  </code></pre>
  
  <p><strong>User</strong>:</p>
  
  <pre><code>class User {
      String login
      String password
      static hasMany = [ holidays : Holiday ]
          static constraints = {
      }
  }
  </code></pre>
  
  <p>I have created a one-many relationships between <code>Holiday</code> and <code>User</code>. Note that I haven't included <code>belongsTo</code> on the <code>Holiday</code> class. Now I have written the following integration test: </p>
  
  <pre><code>void testWithoutBelongsTo() {       
          def user1 = new User(login:"anto", password:"secret")
          user1.save()
          def holiday1 = new Holiday(justification:"went to trip")
          holiday1.save()
          user1.addToHolidays(holiday1)
          assertEquals 1, User.get(user1.id).holidays.size()
          user1.delete()
          assertFalse User.exists(user1.id)
          assertFalse Holiday.exists(holiday1.id)
      }
  </code></pre>
  
  <p>Clearly in the above test case, I'm deleting only the <code>user1</code> instance, but when I run with assert statements I can see that GORM have implicitly deleted <code>holiday1</code>, too. And my Test cases have <em>PASSED</em>! How this can happen, even though I haven't given <code>belongsTo</code> keyword in <code>Holiday</code> class? </p>
  
  <p>I'm using Grails version 1.3.7.</p>