title: Groovy SQL + Gorm under same session/transaction
body: <p>Please go through the simple scenario below, I couldn't find a better way to ask the question in textual form:</p>
  
  <p>Two domain objects and a transactional service:</p>
  
  <pre><code>A {
   int id
   String prop1
   B b
   static constraints = {b nullable:true}
  }
  
  B {
   int id
   String prop1
   // not worring about belongsTo here
  }
  
  
  
  SomeService {
  
   def transactional = true
   def sessionFactory
  
   def aTransactionalMethod() {
    Sql sql = new Sql(sessionFactory.currentSession.connection())
  
    sql# create A some how with sql query leaving property b as null.
  
   A a = A.findById(...)
   //a.b must be null here, never mind
  
   sql# create B object somehow with sql query.
  
   // should a.b be available now? I'm getting null here.. session.currentSession.refresh(a) resolves the issue but why is that?
   }
  }
  </code></pre>