title: Update top(1) null in column in PostgreSQL
body: <p>I've got a table with the following structure:</p>
  
  <pre><code>ULI       DLI       others
  itemu1    itemd1    itemo1
  itemu2    itemd2    itemo2
  itemu3    NULL      itemo3
  itemu4    NULL      NULL
  </code></pre>
  
  <p>My goal is to insert a value into the column DLI where the first NULL is. I have tried variations of the following query but they don't work:</p>
  
  <pre><code>"UPDATE COUNT(1) table SET 'DLI' = @DLI WHERE 'DLI' IS NULL;"
  </code></pre>
  
  <p>I always get a syntax error with "count" and I'm not sure what the best way is to solve it.</p>