title: The proper way to add columns to Sales Order Grid in Magento 1.7
body: <p>I am looking for a way to add columns to the Sales/Order grid in Magento. There are many tutorials but I find that they involve overriding Core files by placing them in the Local CodePool and this isn't always good practice.</p>
  
  <p>I am trying to add:</p>
  
  <p>Postcode,
  Address, 
  Email,
  Telephone,
  OrderID,
  CustomerID</p>
  
  <p>If anyone can share a solution or extension that I could use to achieve this without the Core override I'd be extremely grateful.</p>
  
  <pre><code>&lt;?xml version="1.0"?&gt;
  &lt;gridcontrol&gt;
      &lt;grids&gt;
          &lt;!-- grid id --&gt;
          &lt;sales_order_grid&gt;
              &lt;shipping_description&gt;
                  &lt;add&gt;
                      &lt;header&gt;Shipping Description&lt;/header&gt;
                      &lt;!-- join shipping description from sales/order table --&gt;
                      &lt;join table="sales/order" condition="main_table.entity_id={{table}}.entity_id" field="shipping_description"/&gt;
                  &lt;/add&gt;
                 &lt;after&gt;status&lt;/after&gt;
              &lt;/shipping_description&gt;
              &lt;shipping_address&gt;
                  &lt;add&gt;
                      &lt;header&gt;Shipping Address&lt;/header&gt;
                      &lt;!-- join shipping description from sales/order table --&gt;
                      &lt;join table="sales/order" condition="main_table.entity_id={{table}}.entity_id" field="shipping_address"/&gt;
                  &lt;/add&gt;
                  &lt;after&gt;status&lt;/after&gt;
              &lt;/shipping_address&gt;
              &lt;Billing_address&gt;
                  &lt;add&gt;
                      &lt;header&gt;Billing Address&lt;/header&gt;
                      &lt;!-- join shipping description from sales/order table --&gt;
                      &lt;join table="sales/order" condition="main_table.entity_id={{table}}.entity_id" field="billing_address"/&gt;
                  &lt;/add&gt;
                  &lt;after&gt;status&lt;/after&gt;
              &lt;/Billing_address&gt;
              &lt;Telephone&gt;
                  &lt;add&gt;
                      &lt;header&gt;Telephone&lt;/header&gt;
                      &lt;!-- join shipping description from sales/order table --&gt;
                      &lt;join table="sales/order" condition="main_table.entity_id={{table}}.entity_id" field="telephone"/&gt;
                  &lt;/add&gt;
                  &lt;after&gt;status&lt;/after&gt;
              &lt;/Telephone&gt;
              &lt;CustomerID&gt;
                  &lt;add&gt;
                      &lt;header&gt;Customer ID&lt;/header&gt;
                      &lt;!-- join shipping description from sales/order table --&gt;
                      &lt;join table="sales/order" condition="main_table.entity_id={{table}}.entity_id" field="customer_id"/&gt;
                  &lt;/add&gt;
                  &lt;after&gt;status&lt;/after&gt;
              &lt;/CustomerID&gt;
          &lt;/sales_order_grid&gt;
      &lt;/grids&gt;
  &lt;/gridcontrol&gt;
  </code></pre>