title: SQLAlchemy: How to Delete with join
body: <p>I have trouble doing such thing bottom with SQLAlchemy:</p>
  
  <pre><code>DELETE a FROM a INNER JOIN b ON b.`aId` = a.`Id` WHERE `b`.`xxx` = ?;
  </code></pre>
  
  <p>As the post here: <a href="https://stackoverflow.com/questions/15023719/sqlalchemy-create-delete-query-using-self-join-on-mysql">SQLAlchemy: Create delete query using self-join on MySQL</a></p>
  
  <p>I've got it's hard to do delete in SQLAlchemy with join.</p>
  
  <p>So I'm now doing like this:</p>
  
  <pre><code>session.execute('DELETE a FROM a INNER JOIN b ON b.`aId` = a.`Id` WHERE `b`.`xxx` = %d;'%xxx)
  </code></pre>
  
  <p>But it just annoy me a lot like about: SQL Injection thing, etc..</p>
  
  <p>Is there any way using SQLAlchemy to solve the problem here? Thanks!</p>