按星期分组的结果

Question

我有一个架构：

item | sales
1      10
1      20
1      30
2      10
2      20
2      30

如何对结果进行分组，如下所示：

item | total
1      60
2      60

我试过

select sum(sales) as total, week from shop
where item = 1
order by total DESC

我不确定如何在没有很多OR条款的情况下使其工作

Answer 1

您必须按item分组才能对每个项目求和，而不是表格中的完整数据

select sum(sales) as total, item
from shop
group by item
order by total DESC

Answer 2

您应该使用group by语句：

select item, sum(sales) as total
from shop
group by item
order by total desc

Answer 3

试试这个：

select item, sum(sales) as total from shop 
GROUP BY item
ORDER BY total DESC