MYSQL 限制结果

Question

我的查询几乎已经完成，但还有最后一个问题需要解决。我的查询如下所示：

//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>';
}

这部分：

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

如果订单状态为 4 或 13，则导致显示结果。问题是在后端我可以多次将其置于这些状态，所以如果我不小心的话更新订单时，会多次添加结果。

这是一种限制该功能仅处理最新更新（在同一个表中具有 date_add ）或限制为 1 的方法吗？

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

也许会有帮助。