根据示例表,您似乎希望分组product
而不是id
。您只需要将Size
列添加到SELECT
列表和GROUP BY
$query = "SELECT
product,
Size,
SUM(Quantity) AS TotalQuantity
FROM inventory
GROUP BY product, Size";
请注意,我添加了一个列别名TotalQuantity
,这将让您更轻松地通过更明智的检索所取得的行的列$row['TotalQuantity']
,而不是$row['SUM(Quantity)']