title: android update database column based on the current column value
body: <p>In android, <code>SQLiteDatabase</code> has a update function</p>
  
  <pre><code>update(String table, ContentValues values, String whereClause, String[] whereArgs)
  </code></pre>
  
  <p>new values in put in <code>values</code><br>
  If I want to update a column A by adding one to it, how should I prepare the ContentValues values variable? I don't think the following would work.</p>
  
  <pre><code>cv.put("A", "A" + 1);
  </code></pre>
  
  <p>I can sure run <code>execSQL</code> with raw sql, but it does not return num of row updated</p>