相关疑难解决方法(0)

我在SQL查询中使用sum()寻求帮助:

SELECT links.id, 
       count(DISTINCT stats.id) as clicks, 
       count(DISTINCT conversions.id) as conversions, 
       sum(conversions.value) as conversion_value 
FROM links 
LEFT OUTER JOIN stats ON links.id = stats.parent_id 
LEFT OUTER JOIN conversions ON links.id = conversions.link_id 
GROUP BY links.id 
ORDER BY links.created desc;

我使用DISTINCT是因为我正在"分组",这确保同一行不会被计算多次.

问题是SUM(conversions.value)多次计算每行的"值"(由于分组)

我基本上想要SUM(conversions.value)为每个DISTINCT conversions.id 做.

那可能吗？