title: How to declare a table class that contains multi-column primary key?
body: <p>The columns of the primary key must be in specific order.</p>
  
  <p>I see some code from document :</p>
  
  <pre><code>class User(Base):
      __tablename__ = 'users'
  
      id = Column(Integer)
  
      __mapper_args__ = {
          'primary_key':[id]
      }
  </code></pre>
  
  <p>But it just does not work (I'm using mysql, and the id primary key will not be generated).
  Any possible solutions? </p>