title: Performing updates/overwrite to tables in Azure SQL Database from Databricks
body: <p>In Azure Databricks the table is already created in the Azure SQL warehouse and I'd like to perform an update to the existing in the azure sql database or overwrite it's contents when my job runs </p>
  
  <p>I am able to append but I am facing issues to perform update/overwrite for performing etl. 
  I have tried the below and but it drops the table and tries to recreate with set of new records which is not what I want. </p>
  
  <pre><code>def insupd(df,tabname):
  df.write.mode("overwrite") \
  .format("jdbc") \
  .option("url", jdbcUrl) \
  .option("dbtable", tabname) \
  .option("user",jdbcUsername) \
  .option("password", jdbcPassword) \
  .option("driver", "com.microsoft.sqlserver.jdbc.SQLServerDriver") \
  .save()
   return True
  </code></pre>
  
  <p>Need to know how I can perform the update/overwrite in my case. Also please let me know require libraries to import.  </p>