title: Point of sales defined
body: <p>I build an inventory and management stock + invoice
  I have a table "invoice"</p>
  
  <pre><code>content: id 
  customer_name
  net_total
  paid
  due
  ordre_date
  </code></pre>
  
  <p>I want to show all net_total for everyday, for week, and for months</p>
  
  <p>I use this query</p>
  
  <pre><code>SELECT *, sum(net_total) as privé 
  FROM invoice 
  GROUP BY order_date 
  </code></pre>
  
  <p>But it's don't show all net_total for each day</p>