php - 除一种情况外的内连接

Question

我有以下统计表:

id | date | user_id | price | additional_price

我的查询如下所示:

SELECT month, sum(price), sum(additional_price)
FROM statistics s
INNER JOIN users u on s.user_id = u.id
AND u.confirmed = 1
GROUP BY MONTH(date);

问题在于，该表中存在价格等于0的行，但additional_price大于0，用户未确认，或者不确认不再存在了。我想将它们计入输出总和。像这样的东西:

SELECT t.month, sum(t.price), sum(t.additional_price)
FROM (

(SELECT month, sum(price), sum(additional_price)
FROM statistics s
INNER JOIN users u on s.user_id = u.id
WHERE u.confirmed = 1
AND s.price > 0
GROUP BY MONTH(date))
UNION
(SELECT month, sum(price), sum(additional_price)
FROM statistics s
WHERE price = 0
GROUP BY MONTH(date))

) AS t
GROUP BY MONTH(t.date);

它会起作用，这就是我想要达到的结果。但查询速度慢、规模大且难以维护。我遇到的主要问题是我不能在这样的表上使用关系:

$statistics = Statistic::join('users');
$statisticsForZeroPrice = Statistic::forZeroPrice();
$result = DB::query()->fromSub($statistics->union($statisticsForZeroPrice), 't')
 ->with('user') // will not work 
 ->groupBy('t.date')
 ->get();

这个问题有更简单的解决方案吗？

Answer 1

我猜你想要一个左连接。从您问题中的有限信息来看，是这样的:

SELECT month, sum(price), sum(additional_price)
FROM statistics s LEFT JOIN
     users u
     ON s.user_id = u.id AND u.confirmed = 1
GROUP BY MONTH(date);

不清楚哪个表应该位于左连接中的第一个。