Question

这里的sql语句很新，所以这个对我来说有点棘手。

我有两张桌子：已售出和产品。已售出（SID，UPC，日期）产品（UPC，名称，品牌）

我需要找到一个品牌超过另一个品牌的商店（sid）。

我认为它是这样的：

select count(*) from sold natural join product 
where count(brand = 'sony') > count(brand = 'samsung');

显然这无效......

Answer 1

SELECT COUNT(*)
FROM (
   SELECT SID
   FROM Sold
   JOIN product
   ON product.UPC = Sold.UPC -- otherwise we have a cartesian product
   GROUP BY SID -- if we need totals _by store_, we need to group on that.
   HAVING SUM(brand='sony') > SUM(brand='samsung')
) Totals.

MySQL - 选择一个计数大于另一个计数的id计数

1 个答案: