title: Join two dataframes on the values present in a specific column in the name_data dataframe using koalas
body: <p>I am trying to join two the dataframes as shown below on the <code>code</code> column values present in the <code>name_data</code> dataframe.</p>
  <p>I have two dataframes shown below and I expect to have a resulting dataframe which would only have the rows from the `team_data<code>dataframe where the corresponding</code>code<code>value column is present in the</code>name_data``` dataframe.</p>
  <p>I am using koalas for this on databricks and I have the following code using the join operation.</p>
  <pre><code>import databricks.koalas as ks
  
  name_data= ks.DataFrame({'code':['123a', '345b', '678c'],
          'id':[1, 2, 3]})
  
  team_data = ks.DataFrame({'code':['123a', '23s', '34a'],
          'id':[1, 2, 3]})
  
  team_data_filtered = team_data.join(name_data.set_index('code'), on='code')
  
  display(team_data_filtered)
  
  </code></pre>
  <p>The expected output would be to see only the following in <code>team_data_filtered</code>.</p>
  <pre><code>Code    id
  '123a'   1
  </code></pre>
  <p>But my code is throwing an error stating that <code> columns overlap but no suffix specified: ['id']</code>.</p>
  <p>May someone help to resolve this issue?</p>