title: flask-marshmallow two db objects in one schema
body: <p>I'm trying to serialize this object, which is a result of a join between two tables:</p>
  
  <pre><code>query_response = [(&lt;Company 2&gt;, &lt;Detail 1&gt;), (&lt;Company 3&gt;, &lt;Detail 2&gt;)]
  </code></pre>
  
  <p>and I'm using this schema:</p>
  
  <pre><code>class CompanyCompleteSchema(Schema):
      company = fields.Nested(CompanySchema)
      detail = fields.Nested(DetailSchema)
  
  companies_complete_schema = CompanyCompleteSchema(many=True)
  </code></pre>
  
  <p>Basically, I'd like to have one schema for the join query. 
  I'm using:</p>
  
  <pre><code>data = companies_complete_schema.dump(query_response)
  </code></pre>
  
  <p>It doesn't work and I can't figure out the problem.
  It just returns:</p>
  
  <pre><code>[{}, {}]
  </code></pre>
  
  <p>Any suggestion is highly appreciated. Thanks.</p>