Parameter binding using GQL in Google App Engine

So, I have this mode:

class Posts(db.Model):
  rand1 = db.FloatProperty()
  #other models here

      

        
        
        
      

    

and this controller:

class Random(webapp.RequestHandler):
  def get(self):    
      rand2 = random.random()
      posts_query = db.GqlQuery("SELECT * FROM Posts WHERE rand1 > :rand2 ORDER BY rand LIMIT 1")
      #Assigning values for Django templating
      template_values = {
          'posts_query': posts_query,
           #test purposes
          'rand2': rand2,
          }

      path = os.path.join(os.path.dirname(__file__), 'templates/random.html')
      self.response.out.write(template.render(path, template_values))

      

        
        
        
      

    

So, when an object is added, a random float (0-1) is generated, and then when I need to grab a random object, I want to be able to just use a simple SELECT query. These are errors with:

BadArgumentError('Missing named arguments for bind, requires argument rand2',)

      

        
        
        
      

    

Now this works if I go:

posts_query = db.GqlQuery("SELECT * FROM Posts WHERE rand1 > 1 ORDER BY rand LIMIT 1")

      

        
        
        
      

    

Thus, my request is incorrect; how to use variable in where statement: S