Question

我尝试在MySQL中进行查询，从3个表中获取数据，并在2个表中进行计算。但我真的不知道该怎么做。

我在PHP代码中有这个来计算“每次点击的Avage成本”：

获取所有广告系列。
```
  SELECT * FROM campaigns;
```

获取广告系列的点击次数：

select SUM(id) as IALT2 from aktivitet where annonce_id = '@@CAMPAIGN_ID' group by ip");

从所有行中获取总计

SELECT SUM(price) as IALT from money where ad = '@@CAMPAIGN_ID' group by id

现在我可以计算出“每次点击费用”

 "IALT / IALT2" = CPC

然后应该说：

select * from campaign order by CPC desc limit 0,1

Answer 1

select * from campaigns C
order by
(
    (select SUM(price) from money where ad = C.CAMPAIGN_ID)
    /
    (select SUM(id) from aktivitet where annonce_id = C.CAMPAIGN_ID)
)desc limit 0,1

只是猜测，但我想你想要这个

从3个表中选择计算

1 个答案: