grouping join query results - mysql

Question

I am trying to write a query that shows me all orders with their options. So far that's done, but when I try to group them by order id it just print a separate row for each option and not the order ID and all its option under it.
I am missing something but can't figure out what is it :)
Here is what I have
$sql = 'SELECT *
FROM `order` RIGHT JOIN `order_option`
on order.order_id=order_option.order_id
where order_status_id = 2
group by order_option.order_option_id';
$retval = mysql_query( $sql, $conn );
if(! $retval )
{
die('Could not get data: ' . mysql_error());
}
while($row = mysql_fetch_array($retval, MYSQL_ASSOC))
{
print "ID:{$row['order_id']} <br> ".
"OPTION NAME: {$row['name']} <br> ".
"VALUE: {$row['value']} <br> ".
"--------------------------------<br>";
}
echo "Fetched data successfully\n";
mysql_close($conn);
?>
**UPDATE 1**
This is how the query worked now
SELECT
o.order_id,
o.name,
o.value,
GROUP_CONCAT(o.order_id, o.name, o.value SEPARATOR ',') AS Options
FROM `order_option` AS o
LEFT JOIN `order` AS oo on o.order_id = oo.order_id
where oo.order_status_id = 2
group by o.order_id

Answer 1

You should GROUP BY order_id instead, and use GROUP_CONCAT to get all the options of an order in the same row:
SELECT
o.order_id,
GROUP_CONCAT(oo.order_option_id SEPARATOR ',') AS Options
FROM `order` AS o
RIGHT JOIN `order_option` AS oo on o.order_id = oo.order_id
where o.order_status_id = 2
group by o.order_id;
SQL Fiddle Demo
If GROUP_CONCAT is not what are you looking for, then you have to use other aggregate functions, but don't include any columns that is not in the GROUP BY clause in the SELECT clause without an aggregate function. Otherwise you will got inconsistent data.
Update 1
The reason your query doesn't work:
SELECT
o.order_id,
o.name,
o.value,
GROUP_CONCAT(o.order_id SEPARATOR ',') AS Options
FROM order_option AS o
LEFT JOIN order AS oo on o.order_id = oo.order_id
where oo.order_status_id = 2
group by o.order_id
Becuase the two columns o.name, o.value in the SELECT clause are not neither in an aggregate function not in the GROUP BY clause, so you are getting inconsistent values of these tow columns, MySQL gets an arbitrary value for them. Try this instead:
SELECT
o.order_id,
o.name,
o.value,
GROUP_CONCAT(o.order_id SEPARATOR ',') AS Options
FROM order_option AS o
LEFT JOIN order AS oo on o.order_id = oo.order_id
where oo.order_status_id = 2
group by o.order_id,
o.name,
o.value;