title: SQL (SQLite) count for null-fields over all columns
body: <p>I've got a table called <code>datapoints</code> with about 150 columns and 2600 rows. I know, 150 columns is too much, but I got this db after importing a csv and it is not possible to shrink the number of columns. </p>
  
  <p>I have to get some statistical stuff out of the data. E.g. one question would be: 
  Give me the total number of fields (of all columns), which are null. Does somebody have any idea how I can do this efficiently?</p>
  
  <p>For one column it isn't a problem:</p>
  
  <pre><code>SELECT count(*) FROM datapoints tb1 where 'tb1'.'column1' is null;
  </code></pre>
  
  <p>But how can I solve this for all columns together, without doing it by hand for every column?</p>
  
  <p>Best, 
  Michael</p>