title: SQLAlchemy: How to cast string value to date in multiple insert statement?
body: <p>I have a list of dict objects</p>
  
  <pre><code>data = [
  {'id': 1, 'dt':'2002-01-02' },
  {'id': 2, 'dt':'2014-01-15' },
  {'id': 3, 'dt':'2005-10-20' }
  ]
  </code></pre>
  
  <p>and a table in sqlite created using sqlalchemy as follows</p>
  
  <pre><code>engine = create_engine(config.SQLALCHEMY_DATABASE_URI)
  metadata = MetaData()
  
  tbl1 = Table('t1', metadata,
                       Column('the_id', Integer, primary_key=True),
                       Column('the_dt', Date))
  
  metadata.create_all(bind=engine)
  
  stmt_insert = tbl1.insert().values(the_id=bindparam('id'), the_dt=bindparam('dt', type_=Date)
  
  with engine.connect() as conn:
      conn.execute(stmt_insert, data)
  </code></pre>
  
  <p>This gives me the following error:</p>
  
  <blockquote>
    <p>sqlalchemy.exc.StatementError: (builtins.TypeError) SQLite Date type
    only accepts Python date objects as input.</p>
  </blockquote>
  
  <p>What do I assign to the "type_" parameter to make this binding work ?</p>