MYSQL GROUP BY和WHERE子句

我有这样的查询运行得很好：MYSQL GROUP BY和WHERE子句

SELECT offers.*, COALESCE(SUM(commission),0) AS revenue, COUNT(commission) AS leads 
FROM offers 
LEFT JOIN offers_revenue AS or ON or.offerid=offers.offerid 
GROUP BY offers.offerid

这将返回我的所有与正确comission报价表中的行相加。

现在我需要添加一个WHERE子句（可以说，当某个条件满足并不总和）：

SELECT offers.*, COALESCE(SUM(commission),0) AS revenue, COUNT(commission) AS leads, reversed 
FROM offers 
LEFT JOIN offers_revenue AS or ON or.offerid=offers.offerid 
WHERE reversed=0 
GROUP BY offers.offerid, reversed

开始我尝试只需添加WHERE子句，但是这回我一个空集的结果，挖掘后我知道，你需要包括你的GROUP BY参数，并将它们包括在SELECT中，但仍然没有结果。

我在这里做错了什么？在第一个查询中，我测试表上的所有结果都被设置为reverse = 0，所以我必须在这里丢失一些东西。

来源

2014-02-19 Jorg Ancrath

'WHERE逆转= 0' ==>'具有相反= 0'编辑：组后添加BY .. .... –

HAVING没有做的伎俩。 –

想必reversed是在or表。您通过比较将left outer join变成inner join。该解决方案是将条件移到on条款：

SELECT o.*, COALESCE(SUM(ofr.commission),0) AS revenue, COUNT(ofr.commission) AS leads, reversed 
FROM offers o LEFT JOIN 
    offers_revenue ofr 
    ON `ofr`.offerid = o.offerid and ofr.reversed = 0 
GROUP BY o.offerid;

来源

2014-02-19 13:56:11

啊！这是我想的首选方式，谢谢！ –

尝试这与IF statment：

SELECT offers.*, if(reversed=0 , 0 , SUM(commission))) AS revenue, 

     COUNT(commission) AS leads, 
     reversed     
FROM offers 
LEFT JOIN offers_revenue AS or ON or.offerid=offers.offerid 
GROUP BY offers.offerid, reversed

来源

2014-02-19 13:44:51

“你的SQL语法错误”（是的，带走了你的评论） –

ahh对不起，我忘了'''现在试试 –

@echo_Me小异议如果不是语句，它是一个函数，是'IF（a， b，c）'是一个陈述。 –

MYSQL GROUP BY和WHERE子句

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