用户kCCpJ0269548(提问者)SELECT
b.\"类别名称\",
c.\"产品名称\",
sum( x.\"数量\" )
FROM
\"订单\" d
LEFT JOIN 订单明细 x ON ( d.\"订单ID\" = x.\"订单ID\" )
LEFT JOIN 产品 c ON ( x.\"产品ID\" = c.\"产品ID\" )
LEFT JOIN 产品类别 b ON ( c.\"类别ID\" = b.\"类别ID\" )
GROUP BY
c.\"产品名称\"
ORDER BY
sum( x.\"数量\" ) DESC