Question

我正在运行一个非常简单的MySQL查询并尝试按销售价值排序数据...数据库中的列设置为十进制（16,2）但是当数据返回时它没有排序任何订单。

这是我的代码：

$query = "
SELECT *
     , SUM(sale_value) 
  FROM sale 
 WHERE week_no = $today
 GROUP  
    BY user_id 
 ORDER 
    BY sale_value DESC
"; 

$result = mysql_query($query) or die(mysql_error());
// Print out result
while($row = mysql_fetch_array($result)){
 echo "Total ". $row['user_id']. " = &pound;". $row['SUM(sale_value)'];
echo "<br />";
}

以下是我得到的结果：

Total 14 = £2195.77
Total 62 = £865.01
Total 52 = £2989.53
Total 42 = £2689.47
Total 51 = £894.51
Total 48 = £962.09
Total 39 = £1161.43
Total 33 = £1341.49
Total 1 = £5989.57
Total 8 = £4937.48
Total 59 = £1377.70
Total 32 = £3063.06
Total 41 = £1937.82
Total 60 = £2981.01
Total 53 = £1050.21
Total 46 = £1836.05
Total 57 = £310.43
Total 19 = £2534.92
Total 5 = £1946.01
Total 56 = £471.00
Total 7 = £865.00
Total 2 = £754.30

有人能发现我做错了吗？

Answer 1

您在匹配的行中按任意值排序，而不是总和。为列添加别名并使用：

SELECT *, SUM(sale_value) as total_sale_value
FROM sale
WHERE week_no = ".$today."
GROUP  BY user_id
ORDER By total_sale_value DESC;

顺便说一下，select *与group by一起使用是一个非常非常非常糟糕的主意。您应该明确列出用于定义每个聚合组的列：

SELECT user_id, SUM(sale_value) as total_sale_value
FROM sale
WHERE week_no = ".$today."
GROUP BY user_id
ORDER By total_sale_value DESC;

Answer 2

您应该order by SUM(sale_value)而不是sale_value

PHP＆amp; MYSQL按十进制列排序

2 个答案: