Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>One of the basic tenets of relational databases is that columns don't hold compound data, which means no arrays. It's also called "<a href="http://en.wikipedia.org/wiki/First_normal_form" rel="nofollow noreferrer">first normal form</a>" (1NF). If you don't want repeated order info within the product query, you can run two queries rather than one, one that gets the orders and the second that gets the products. </p> <p>Since the result of the query is being processed anyway, you can also take care of aggregation within PHP once you get the result. You can aggregate first:</p> <pre><code>$orders=array(); while ($row = $result-&gt;fetch()) { if (! isset($orders[$row['order_id']])) { $orders[$row['order_id']] = new Order($row); } else { $orders[$row['order_id']]-&gt;addProducts($row); } } </code></pre> <p>(assuming a suitable Order class), or aggregate in-line:</p> <pre><code>class OrderList { ... function printXML($result) { $currOrderID = null; echo '&lt;orders&gt;' while ($row = $result-&gt;fetch()) { if ($currOrderID != $row['order_id']) { $this-&gt;closeOrder(); $this-&gt;openOrder($row); } $this-&gt;printProduct($row); } $this-&gt;closeOrder(); echo '&lt;/orders&gt;'; } function openOrder($row) { echo "&lt;order id='$row[order_id]'&gt;&lt;total&gt;$row[order_total]&lt;/total&gt;"; $this-&gt;printCustomer($row); echo '&lt;products&gt;'; } function printProduct($row) { echo "&lt;product&gt;&lt;title&gt;$row[title]&lt;/title&gt;&lt;price&gt;$row[price]&lt;/price&gt;&lt;/product&gt;\n"; } function closeOrder() { echo '&lt;/products&gt;&lt;/order&gt;'; } function printCustomer($row) { echo &lt;&lt;EOS; &lt;customer&gt; &lt;email&gt;$row[primary_email]&lt;/email&gt; &lt;first_name&gt;$row[delivery_first_name]&lt;/first_name&gt; ... EOS; $this-&gt;printAddress($row); echo '&lt;/customer&gt;'; } function printAddress($row) { echo &lt;&lt;EOS; &lt;address&gt; &lt;street line="1"&gt;$row[delivery_street1]&lt;/street&gt; &lt;street line="2"&gt;$row[delivery_street2]&lt;/street&gt; ... &lt;/address&gt; EOS; } } </code></pre> <p>Of course, the specifics of the above is not a good design for production code. The <code>print*</code> methods (and even order printing, via the <code>openOrder</code> and <code>closeOrder</code>) probably deserve to be OrderWriter, CustomerWriter, AddressWriter and ProductWriter classes. You might also want to use <a href="http://php.net/XMLWriter" rel="nofollow noreferrer">XMLWriter</a> rather than echoing.</p>
    singulars
    1. This table or related slice is empty.
    1. POSQL nested query in stored in an array?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USoutis
    1. USoutis
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POSQL nested query in stored in an array?
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COthanks for the detailed response - I'm using the DOM to take care of the XML stuff. I'l have a go with adapting your example to suit my project. Allan
      singulars
      1. PO
      1. USAllan
    2. COTake my advice about the *Writer classes to heart. I'm very tempted to change the example.
      singulars
      1. PO
      1. USoutis
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload