MULTIPLE LEFT JOINS AND ORDER BY - mysql

Question

I have following query on in my file:
function getItems($ShowFeatured,$OrderBy,$Order,$amountShow,$ShowPropertyID)
{
switch($OrderBy) {
case 0 :
$OrderBy = 'p.id';
break;
case 1 :
$OrderBy = 'p.name';
break;
case 2 :
$OrderBy = 'p.price';
break;
case 3 :
$OrderBy = 'p.hits';
break;
case 4 :
$OrderBy = 'p.refresh_time';
break;
}
switch($Order) {
case 0 :
$Order = 'ASC';
break;
case 1 :
$Order = 'DESC';
break;
}
if($ShowPropertyID){$where= 'WHERE p.id IN ('.$ShowPropertyID.')';}else{$where= 'WHERE p.published = 1 ';}
if($ShowFeatured){$sqlFeatured= ' AND p.featured = 1';}
$db = &JFactory::getDBO();
$query = 'SELECT p.*, i.name as imagename,c.id as key1,c.name as name_category,t.id as key5,t.name as name_type,cy.id as key2,cy.name as name_country,s.id as key3,s.name as name_state,l.id as key4,l.name as name_locality,'
. ' CASE WHEN CHAR_LENGTH(p.alias) THEN CONCAT_WS(":", p.id, p.alias) ELSE p.id END as Pslug,'
. ' CASE WHEN CHAR_LENGTH(c.alias) THEN CONCAT_WS(":", c.id, c.alias) ELSE c.id END as Cslug,'
. ' CASE WHEN CHAR_LENGTH(cy.alias) THEN CONCAT_WS(":", cy.id, cy.alias) ELSE cy.id END as CYslug,'
. ' CASE WHEN CHAR_LENGTH(s.alias) THEN CONCAT_WS(":", s.id, s.alias) ELSE s.id END as Sslug,'
. ' CASE WHEN CHAR_LENGTH(l.alias) THEN CONCAT_WS(":", l.id, l.alias) ELSE l.id END as Lslug, '
. ' CASE WHEN CHAR_LENGTH(t.alias) THEN CONCAT_WS(":", t.id, t.alias) ELSE t.id END as Tslug '
. ' FROM #__properties_products AS p '
. ' LEFT JOIN #__properties_country AS cy ON cy.id = p.cyid '
. ' LEFT JOIN #__properties_state AS s ON s.id = p.sid '
. ' LEFT JOIN #__properties_locality AS l ON l.id = p.lid '
. ' LEFT JOIN #__properties_category AS c ON c.id = p.cid '
. ' LEFT JOIN #__properties_type AS t ON t.id = p.type '
. ' LEFT JOIN #__properties_images AS i ON p.id = i.parent '
. $where
. $sqlFeatured
. ' GROUP BY p.id '
. ' ORDER BY '.$OrderBy.' '.$Order
. ' LIMIT '.$amountShow;
$db->setQuery($query);
$items = $db->loadObjectList();
// $items = ($items = $db->loadObjectList())?$items:array();
//echo str_replace('#_','jos',$query);
return $items;
Part to get an image is following:
. ' LEFT JOIN #__properties_images AS i ON p.id = i.parent '
This query orders images by i.parent - image that I get I don't like. In my database I have row i.ordering - is it possible to order images by i.ordering on above query?
Thanks.

Answer 1

Something like this for you query I think will do what you want.
$query = 'SELECT p.*, i.name as imagename,c.id as key1,c.name as name_category,t.id as key5,t.name as name_type,cy.id as key2,cy.name as name_country,s.id as key3,s.name as name_state,l.id as key4,l.name as name_locality,'
. ' CASE WHEN CHAR_LENGTH(p.alias) THEN CONCAT_WS(":", p.id, p.alias) ELSE p.id END as Pslug,'
. ' CASE WHEN CHAR_LENGTH(c.alias) THEN CONCAT_WS(":", c.id, c.alias) ELSE c.id END as Cslug,'
. ' CASE WHEN CHAR_LENGTH(cy.alias) THEN CONCAT_WS(":", cy.id, cy.alias) ELSE cy.id END as CYslug,'
. ' CASE WHEN CHAR_LENGTH(s.alias) THEN CONCAT_WS(":", s.id, s.alias) ELSE s.id END as Sslug,'
. ' CASE WHEN CHAR_LENGTH(l.alias) THEN CONCAT_WS(":", l.id, l.alias) ELSE l.id END as Lslug, '
. ' CASE WHEN CHAR_LENGTH(t.alias) THEN CONCAT_WS(":", t.id, t.alias) ELSE t.id END as Tslug '
. ' FROM #__properties_products AS p '
. ' LEFT JOIN #__properties_country AS cy ON cy.id = p.cyid '
. ' LEFT JOIN #__properties_state AS s ON s.id = p.sid '
. ' LEFT JOIN #__properties_locality AS l ON l.id = p.lid '
. ' LEFT JOIN #__properties_category AS c ON c.id = p.cid '
. ' LEFT JOIN #__properties_type AS t ON t.id = p.type '
. ' LEFT JOIN (SELECT parent, MAX(ordering) AS MostImportant FROM #__properties_images GROUP BY parent) x ON p.id = x.parent '
. ' LEFT JOIN #__properties_images AS i ON x.parent = i.parent AND x.MostImportant = i.ordering '
. $where
. $sqlFeatured
. ' GROUP BY p.id '
. ' ORDER BY '.$OrderBy.' '.$Order
. ' LIMIT '.$amountShow;
You might want to use MIN instead of MAX depending on which way the ordering works