title: SQLalchemy: alembic bulk_insert() fails
body: <p>Before you flag this as a duplicate:</p>
  
  <p>I did take a look at this <a href="https://stackoverflow.com/questions/15725859/sqlalchemy-alembic-bulk-insert-fails-str-object-has-no-attribute-autoincre">question/answer</a>, and I did do what it suggests, but when I do add this code:</p>
  
  <pre><code>permslookup = sa.Table('permslookup',
      sa.Column('perms_lookup_id', primary_key=True),
      sa.Column('name', sa.Unicode(40), index=True),
      sa.Column('description', sa.Text),
      sa.Column('value', sa.Numeric(10, 2)),
      sa.Column('ttype', sa.PickleType(), index=True),
      sa.Column('permission', sa.Unicode(40), index=True),
      sa.Column('options', sa.PickleType())
      )
  </code></pre>
  
  <p>and then run <code>alembic upgrade head</code>, I get the following error:</p>
  
  <pre><code>AttributeError: Neither 'Column' object nor 'Comparator' object has an attribute 'schema'
  </code></pre>
  
  <p>When I examine the full stack trace, I notice that This is causing the error:</p>
  
  <pre><code>sa.Column('options', sa.PickleType())
  </code></pre>
  
  <p>This is the last line of the above code... How can I resolve this? I have not a clue what how to solve it... Help of any kind would be appreciated. </p>
  
  <p>Here is the data I want to insert:</p>
  
  <pre><code>op.bulk_insert('permslookup',
      [
          {
              'id': 1,
              'name': 'accounts',
              'description': """ Have permission to do all transactions """,
              'value': 1,
              'ttype': ['cash', 'loan', 'mgmt', 'deposit', 'adjustments'],
              'permission': 'accounts',
              'options': None
          },
          {
              'id': 2,
              'name': 'agent_manage',
              'description': """ Have permission to do cash, cash, loan and Management Discretion transactions """,
              'value': 2,
              'ttype': ['cash', 'loan', 'mgmt'],
              'permission': 'agent_manage',
              'options': None
          },
          {
              'id': 3,
              'name': 'corrections',
              'description': """ Have permission to do cash, loan and adjustments transactions """,
              'value': 3,
              'ttype': ['cash', 'loan', 'adjustments'],
              'permission': 'corrections',
              'options': None
          },
          {
              'id': 4,
              'name': 'cashup',
              'description': """ Have permission to do cash and loan transactions """,
              'value': 4,
              'ttype': ['cash', 'loan'],
              'permission': 'cashup',
              'options': None
          },
  
      ]
  )
  </code></pre>
  
  <p>The original error I get when trying to run the <code>bulk_insert</code> is:</p>
  
  <pre><code>AttributeError: 'str' object has no attribute '_autoincrement_column'
  </code></pre>