title: How to define the query filter for the following situation?
body: <p>I have defined my model as following , and how to define a query to filter the Sanity_Test set which the associated Test_Product's product name are in the specified name list ? Many thanks</p>
  
  <p>For example:</p>
  
  <ol>
  <li><p>Sanity_Test_A contains Test_Product_A(Product name was A) , Test_Product_B(Product name was B)</p></li>
  <li><p>Sanity_Test_B contains Test_Product_C(Product name was A) , Test_Product_D(Product name was C)</p></li>
  <li><p>I want to filter the Sanity_Test record list which it's Test_Product record's Product name is A</p></li>
  </ol>
  
  <h1>APP : CT.model</h1>
  
  <pre><code>class Sanity_Test(models.Model):
  
      build        = models.OneToOneField('CI.Build')                                                           
      system_test  = models.ForeignKey(System_Test,null=True,blank=True)
  
      ......
  
  
  class Test_Product(models.Model):
  
      product     = models.ForeignKey('CI.Product',verbose_name='Product')            
      sanity_test = models.ForeignKey(Sanity_Test)
  
      ......
  
  
  # APP : CI.model 
  class Product(models.Model):
  
      name = models.CharField(max_length=255,unique=True)
  
      ......
  </code></pre>
  
  <p><a href="http://i.stack.imgur.com/vZSzZ.png" rel="nofollow">The Test_Product Record Info</a></p>