Display information from associated table? - php

Question

I am running this statement which works fine....
$sql = "SELECT skill,SUM(quantity) as sum FROM skills
WHERE userid = $userid
GROUP BY skill";
My problem is the column skill stores the value from table agency_skills which has a column that contains the name of the skill.
I am trying to figure out how to display the name of the skill rather than the value stored in the skills table?
This is the entire code I am working with.....
<?php
defined( '_JEXEC' ) or die;
$db = JFactory::getDBO();
$user =& JFactory::getUser();
$userid = $user->get('id');
$sql = "SELECT skill,SUM(quantity) as sum FROM skills
WHERE userid = $userid
GROUP BY skill";
$db->setQuery($sql);
$rows = $db->loadObjectList();
?>
<style>
table, td, th
{
border-bottom:1px solid black;
}
{
th
background-color:#000000
color:#FFF
}
</style>
<table>
<tr>
<th width="195">Skill</th> <th width="195">Total Completed</th>
</tr>
</table>
<table>
<?PHP foreach ($rows as $row): ?>
<tr>
<td width="200"> <?php echo $row->skill?> </td>
<td width="190"> <?php echo $row->sum ?> </td>
</tr>
<?php endforeach ?>
</table>

Answer 1

You can join that table like this
SELECT as.skillname,
SUM(s.quantity) as sum
FROM agency_skills as `as`
left outer join skills as s on s.skill = as.id
WHERE s.userid = $userid
GROUP BY as.skillname
If you use a left outer join instead of the default inner join you get even skills that are not present in the skills table.
Simplified SQL Fiddle demo