title: Sqlite3 - How to import NULL values from csv
body: <p>I have dumped a mysql table as CSV. In this CSV file, the NULL values are written as <code>\N</code><br>
  Now I want to import this data into sqlite database, but I am unable to tell sqlite that <code>\N</code> are null values. It is treating it as a string and that column value is stored as "\N" instead of NULL.</p>
  
  <p>Can anyone guide in how to use <code>.nullvalue</code> dot command from sqlite. I am unable to set <code>\N</code> as nullvalue.<br></p>
  
  <pre><code>sqlite&gt; .show
  nullvalue: ""
  sqlite&gt; .nullvalue \N
  sqlite&gt; .show
  nullvalue: "N"
  sqlite&gt; .nullvalue '\N'
  sqlite&gt; .show
  nullvalue: "\\N"
  sqlite&gt; .nullvalue "\N"
  sqlite&gt; .show
  nullvalue: "N"
  sqlite&gt; .nullvalue \\N
  sqlite&gt; .show
  nullvalue: "\\N"
  sqlite&gt; .nullvalue '\'N
  Usage: .nullvalue STRING
  sqlite&gt; .nullvalue '\\'N
  Usage: .nullvalue STRING
  sqlite&gt; .nullvalue \\N
  sqlite&gt; .show
  nullvalue: "\\N"
  sqlite&gt;
  </code></pre>
  
  <p>This is the output after every value of <code>nullvalue</code></p>
  
  <pre><code>sqlite&gt; .import /tmp/mysqlDump.csv employee
  sqlite&gt; select count(*) from employee where updatedon='\N';
  94143
  sqlite&gt; select count(*) from employee where updatedon is null;
  0
  </code></pre>
  
  <p><strong>How can I tell sqlite to treat <code>\N</code> as NULL value?</strong> I cannot use empty string as NULL value as my data contains empty strings.</p>