title: psycopg2.ProgrammingError: column "none" does not exist - Update Statement
body: <p>I keep encountering the error "psycopg2.ProgrammingError: column "none" does not exist".</p>
  
  <p>I have read the <a href="http://initd.org/psycopg/docs/usage.html#passing-parameters-to-sql-queries" rel="nofollow">psycopg2 documentation</a> and looked at other posts on this error, however, many are specific to an <strong>insert query</strong> rather than an <strong>update query</strong>.</p>
  
  <p>My code is as follows:-</p>
  
  <pre><code>def send_to_sql(identity,list1,list2,list3):
      userid = 30
      Fixture_No = None
      Home_Side_Score = None
      Away_Side_Score = None
      conn = psycopg2.connect("dbname='Euro2016' user='postgres' host='localhost' password='##passwordhere##'")
      cur = conn.cursor()
      cur.execute("""UPDATE "Predictions" SET userid = %r, "Fixture_No" = %r, "Home_Side_Score" = %r, "Away_Side_Score" = %r WHERE "Predictions"."userid" = %r AND "Predictions"."Fixture_No" = %r """ % (userid, Fixture_No, Home_Side_Score, Away_Side_Score, userid, Fixture_No))
      conn.commit()
      cur.close()
      conn.close()
  </code></pre>
  
  <p>This code works fine if scores and fixture number I am trying to pass are numbers but when a None entry is made, the code falls on its face. Somebody save me...</p>