MYSQL限制结果

Question

我已经完成了我的查询，但仍然有最后一个问题需要解决。我的查询是这样的：

//execute the SQL query and return records 
$result = mysql_query("SELECT SUM(ps_order_detail.product_weight) * IF(COUNT(ps_order_detail.id_order_detail) > 50, 1.2, 1) 
as total_provision, COUNT(ps_order_detail.id_order_detail) as antal_ordrar, ps_customer.firstname 
        FROM ps_order_detail 
        JOIN ps_orders ON ps_order_detail.id_order = ps_orders.id_order 
        JOIN ps_order_history ON ps_orders.id_order = ps_order_history.id_order 
        JOIN ps_customer ON ps_orders.id_customer = ps_customer.id_customer 
        WHERE MONTH(ps_order_history.date_add) = MONTH(CURDATE()) AND (ps_order_history.id_order_state) = '4' OR (ps_order_history.id_order_state) = '13' 
        GROUP BY ps_orders.id_customer 
        ORDER BY SUM(ps_order_detail.product_weight) DESC 

"); 


echo "<br>"; 
echo ("<img src=chart.php>"); 
echo "<br>"; 
echo ("<img src=chart_prov.php>"); 

//fetch tha data from the database 
while ($row = mysql_fetch_array($result)) 
{ 
    echo '<font size="3">'; 
    echo " Namn: ".$row{'firstname'}. ""; 
    echo " Provision: ".$row{'total_provision'}. ""; 
    echo " Abonnemang: ".$row{'antal_ordrar'}. ""; 
    echo '<br>'; 
    echo '</font size>'; 
} 

这一部分：

AND (ps_order_history.id_order_state) = '4' OR (ps_order_history.id_order_state) = '13' 

导致的结果，如果订单的状态是4或13的问题是，在后台我可以把要显示它在这些状态很多次，所以如果我在更新订单时不小心，它会多次添加结果。

是否限制该函数只处理最新更新（在同一个表中具有date_add）或限制为1？

Answer 1

尝试使用

SELECT SUM(ps_order_detail.product_weight) * IF(COUNT(ps_order_detail.id_order_detail) > 50, 1.2, 1) 
as total_provision, COUNT(ps_order_detail.id_order_detail) as antal_ordrar, ps_customer.firstname 
       FROM ps_order_detail 
       JOIN ps_orders ON ps_order_detail.id_order = ps_orders.id_order 
       JOIN ps_order_history ON ps_orders.id_order = ps_order_history.id_order     
       JOIN ps_customer ON ps_orders.id_customer = ps_customer.id_customer 
       WHERE ps_order_history.id = (select ps_order_history.id from ps_order_history where ps_orders.id_order = ps_order_history.id_order and MONTH(ps_order_history.date_add) = MONTH(CURDATE()) AND (ps_order_history.id_order_state) = '4' OR (ps_order_history.id_order_state) = '13' order by ps_order_history.date_add desc limit 1) 
       GROUP BY ps_orders.id_customer 
       ORDER BY SUM(ps_order_detail.product_weight) DESC 

也许会有所帮助。