title: MS-Access - why can't this update query fill empty cells?
body: <p>In MS-Access database, table called NewTable3</p>
  
  <p>colname is a text column containing lot of empty cells or blanks.</p>
  
  <p>i want to put ? character in empty cells . when i run the query</p>
  
  <pre><code>UPDATE NewTable3 SET colname = '?' WHERE ISNULL(colname) ; 
  </code></pre>
  
  <p>This query updates 0 records why .  what is wrong with this query</p>