Hi,
I think that it's either because you're using an old version of MySQL or that you have the ONLY_FULL_GROUP_BY setting of MySQL activated:
dev.mysql.com/doc/refman/5.7/en/sql-mode...e_only_full_group_by
Add the code:
,'group' => 'hk_order.order_id'
after the code:
'get' => 'object',
'select' => array(
'SUM(hk_order.order_full_price) as value',
'hk_order.order_currency_id as currency'
),
'tables' => hikashop_table('order') . ' AS hk_order ',
'filters' => array(
'order_type' => 'hk_order.order_type = '.$order_type.'',
'order_status' => ('hk_order.order_status IN ('.implode(',', $valid_order_statuses).')'),
'order_created' => ($created_status ?
'hk_order.order_created >= {DATE_START} AND ({DATE_END} <= 0 OR hk_order.order_created <= {DATE_END})':
'hk_order.order_invoice_created >= {DATE_START} AND ({DATE_END} <= 0 OR hk_order.order_invoice_created <= {DATE_END})'),
)
in the file administrator/components/com_hikashop/classes/statistics.php and that should fix the problem.