title: Pandas to_sql doesn't insert any data in my table
body: <p>I am trying to insert some data in a table I have created.
  I have a data frame that looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/mslic.png" rel="noreferrer"><img src="https://i.stack.imgur.com/mslic.png" alt="dataframe"></a></p>
  
  <p>I created a table:</p>
  
  <pre><code>create table online.ds_attribution_probabilities
  (
  attribution_type text,
  channel text,
  date date ,
  value float
  )
  </code></pre>
  
  <p>And I am running this python script:</p>
  
  <pre><code>engine = create_engine("postgresql://@e.eu-central-1.redshift.amazonaws.com:5439/mdhclient_encoding=utf8")
  connection = engine.raw_connection()
  result.to_sql('online.ds_attribution_probabilities', con=engine, index = False, if_exists = 'append')
  </code></pre>
  
  <p>I get no error, but when I check there are no data in my table. What can be wrong? Do I have to commit or do an extra step?</p>