mysql按类别查询订单顶部销售

Question

在如何执行此查询时遇到问题。有三个类别，ship,car,plane。我想按大多数销售来订购类别。

这里是SQL小提琴http://sqlfiddle.com/#!2/e3344/1

下面是表值

id | name  | sales | category | 
    1 | mike  | 2 | ship | 
    2 | john  | 11 | car | 
    3 | david  | 13 | ship | 
    4 | pablo  | 24 | car | 
    5 | greg  | 13 | car | 
    6 | nick  | 1 | ship | 
    7 | anderson | 19 | ship | 
    8 | matt  | 10 | plane | 
    9 | robbie  | 3 | ship | 
    10 | victor  | 1 | ship | 
    11 | ben   | 11 | plane | 
    12 | rick  | 6 | ship | 
    13 | christopher | 16 | car | 
    14 | steve  | 8 | ship | 
    15 | claudio  | 9 | plane | 

如何添加了按类别和顺序降序总销售额？

Answer 1

试试group by和order by声明。

SELECT category, sum(sales) 
FROM table 
GROUP BY category 
ORDER BY sum(sales) DESC 

编辑 就像一个建议。您的“类别”应该是数据库模型中的额外实体。