Group By Issue converting MySQL to PostgreSQL - mysql

Question

I am trying to convert an old symfony 1.4 app from MySQL to PostgreSQL.
I keep running into the same issue over and over again.
I have some long joins and it is always complaining about having to have a Group By... and in some cases I add the Group By and it asks for another one.
I am new to postgres and I have absolutely no idea what is going on.
Here are the doctrine queries and error messages.
public function getClassifieds($gs_id, $sort_param, $sorter) {
$q = Doctrine_Query::create()
->select('a.*, u.*, t.*,ug.*,ur.*, avg(ur.rating) as rating ')
->from('Items a')
->leftJoin('a.MonitoredAds ma ON ma.item_id = a.id')
->leftJoin('a.GameCategories gc ON gc.game_id = a.game_id')
->leftJoin('a.User u ON u.id = a.user_id')
->leftJoin('u.Profile ug ON ug.user_id = u.id')
->leftJoin('a.UserRatings ur ON ug.user_id = ur.seller_id')
->where('a.game_server_id = ?', $gs_id)
->andWhere('a.quantity > ?', 0);
switch ($sorter) {
case 'datetime_oldest_to_newist':
$q->orderBy('a.created_at asc');
break;
case 'datetime_newest_to_oldest':
$q->orderBy('a.created_at desc');
break;
case 'price_lowest_to_highest':
$q->orderBy('a.price + 0 ASC');
break;
case 'price_highest_to_lowest':
$q->orderBy('a.price + 0 DESC');
break;
case 'quantity_lowest_to_highest';
$q->orderBy('a.quantity asc');
break;
case 'quantity_highest_to_lowest';
$q->orderBy('a.quantity desc');
break;
case 'quantity_highest_to_lowest';
$q->orderBy('a.quantity desc');
break;
case 'sortby_usernameasc':
$q->orderBy('u.username asc');
break;
case 'sortby_usernamedesc':
$q->orderBy('u.username desc');
break;
case 'sortby_userstatus':
$q->orderBy('ug.user_status asc');
break;
}
return $q;
}
Gives Me this error message
SQLSTATE[42803]: Grouping error: 7 ERROR: column "i.id" must appear in the GROUP BY clause or be used in an aggregate function
LINE 1: SELECT i.id AS i__id, i.featured AS i__featured, i.status AS...
So I change the code to ...
->andWhere('a.quantity > ?', 0)
->groupBy('a.id');
Then I get a new error...
SQLSTATE[42803]: Grouping error: 7 ERROR: column "s.id" must appear in the GROUP BY clause or be used in an aggregate function
LINE 1: ... AS i__created_at, i.updated_at AS i__updated_at, s.id AS s_...
I stopped here because this is changing the behaviour of the query in a major way and I really don't know what's going on.
I am not afraid of reading the docs but I don't even know where to start.
If you know what the issue could be please let me know. If you know where I should be looking in the docs please let me know that as well.
Thank you in advance.
Scott

Answer 1

It is not correct for PostgreSQL without GROUP BY all columns besides ur.rating:
->select('a.*, u.*, t.*,ug.*,ur.*, avg(ur.rating) as rating ')
Every selected and ordered column must be in GROUP BY or in agregate function.
For example, rewrite query:
->select('u.id, avg(ur.rating) as rating ')
...
->orderBy('u.id');
->groupBy('u.id');