title: How to change case of whole pyspark dataframe to lower or upper
body: <p>I am trying to apply pyspark sql functions hash algorithm for every row in two dataframes to identify the differences. Hash algorithm is case sensitive .i.e. if column contains 'APPLE' and 'Apple' are considered as two different values, so I want to change the case for both dataframes to either upper or lower. I am able to achieve only for dataframe headers but not for dataframe values.Please help</p>
  
  <pre><code>#Code for Dataframe column headers
  self.df_db1 =self.df_db1.toDF(*[c.lower() for c in self.df_db1.columns])
  </code></pre>