title: NHibernate inner join gives "Path expected for join"
body: <p>I have three Tables:</p>
  
  <pre><code>- Person
  - User
  - PersonSecret
  </code></pre>
  
  <p>where PersonSecret reference to Person and User:</p>
  
  <pre><code>&lt;class name="PersonSecret" table="PersonSecret" lazy="false"  &gt;
  &lt;id name="Id" column="Id" type="Guid"&gt;      
                  &lt;generator class="assigned"/&gt;
  &lt;/id&gt;
  ...
  &lt;many-to-one  name="Person" class="Person" foreign-key="FK_Person_PersonSecret" lazy="proxy" fetch="select"&gt;
      &lt;column name="PersonId"/&gt;
  &lt;/many-to-one&gt;
  &lt;many-to-one  name="User" class="User" foreign-key="FK_User_PersonSecret" lazy="proxy" fetch="select"&gt;
      &lt;column name="UserId"/&gt;
  &lt;/many-to-one&gt;
  </code></pre>
  
  <p></p>
  
  <p>This is the mapping from User to PersonSecret:</p>
  
  <pre><code>&lt;set name="PersonSecrets" lazy="true" inverse="true" cascade="save-update" &gt;
  &lt;key&gt;
      &lt;column name="UserId"/&gt;
  &lt;/key&gt;
  &lt;one-to-many class="PersonSecret"/&gt;
  </code></pre>
  
  <p></p>
  
  <p>And this from Person to PersonSecret:</p>
  
  <pre><code>&lt;set name="PersonSecrets" lazy="true" inverse="true" cascade="save-update" &gt;
  &lt;key&gt;
      &lt;column name="PersonId"/&gt;
  &lt;/key&gt;
  &lt;one-to-many class="PersonSecret"/&gt;
  </code></pre>
  
  <p></p>
  
  <p>Now, i try to select all Persons, which has a Entry in PersonSecret for a specific User:</p>
  
  <pre><code>var query = this.Session.CreateQuery(@"from Person a inner join PersonSecret b 
            where b.UserId = :userId and b.RemindeBirthday = :remind");
  </code></pre>
  
  <p>This gives me now the ExceptionMessage: "Path expected for join"</p>
  
  <p>Can someone help me, what I am doing wrong? - Thanks.</p>