如何从产品表中创建一个包含 5 个价格范围的范围

Question

我有一个包含价格和主类别列的产品表。

我想查询我的数据库以查找给定类别（或所有类别）的价格范围。然后将这个价格范围分成适当数量的价格范围，即 £0-£5 £5-£10 等...

我不知道该怎么做；我需要用 php 来做这一切吗？

编辑： 稍微考虑了一下，澄清一下，我想结束，以便列出任何类别，我可以显示大约 4 个价格范围，产品数量大致相同每个。我无法解决这个问题:(

Answer 1

每个类别的最低和最高价格：

SELECT category, min(price) as min_price, max(price) as max_price
from Products
Group BY category

对于直接在查询中的范围，您可以这样做

SELECT
    category,
    SUM(CASE WHEN price BETWEEN 0 AND 5 THEN 1 ELSE 0 END) as zero-five,
    SUM(CASE WHEN price BETWEEN 5 AND 10 THEN 1 ELSE 0 END) as five-ten,
    ...
from Products
Group BY category

产量

Category  zero-five  five-ten
Cat1        2          4
Cat2        3          6

或

SELECT category, range, count(*)
FROM (
    SELECT 
        category,
        CASE WHEN price BETWEEN 0 to 5 THEN '0-5'
             WHEN price BETWEEN 5 to 10 THEN '5-10'
             ...
             ELSE '10+'
        END as range
    FROM products
)
group by category, range

产量

Category  range count
Cat1       0-5    2      
Cat1       5-10   4      
Cat1       10+    0
Cat2       0-5    3      
Cat2       5-10   6      
Cat2       10+    0

Answer 2

$sql = "
SELECT P1.category as category, min(P1.price) as min_price, max(P2.price) as max_price
FROM Products P1 join Products P2 on P1.category=P2.category
Group BY category
";
<table width="300" border="1">
<tr>
<td><b>category</b></td>
<td><b>min_price</b></td>
<td><b>max_price</b></td>
</tr>
$result = mysql_query($sql);
while($row = mysql_fetch_array($result))
{
//print data
?>
<tr>
<td><? echo $row['category']; ?></td>
<td><? echo $row['min_price']; ?></td>
<td><? echo $row['max_price']; ?></td>
</tr>
<?
}
?>

Answer 3

不确定您的表结构，但这会在您的产品表中获取唯一价格：

select distinct price from products order by price desc;

从这里开始，我可能会开始使用 PHP。您希望如何将这些价格分成几组？