mysql - 联合选择列不匹配

我的问题是：

SELECT
    FROM_UNIXTIME( date_added,  '%m-%d-%Y' ) AS formatted_date,
    SUM( tb =1 ) AS sum_users,
    SUM( tb =2 ) AS sum_links,
    SUM( tb =3 ) AS sum_ads,
    SUM( tb =4 ) AS sum_actions
FROM (
    SELECT date_added, 1 AS tb
        FROM users_list WHERE 1=1
    UNION ALL
    SELECT date_added, 2
        FROM users_links WHERE 1=1
    UNION ALL
    SELECT date_served, 3
        FROM ads_served WHERE 1=1
    UNION ALL
    SELECT date_served, 4
        FROM actions WHERE 1=1
) AS t
GROUP BY formatted_date
ORDER BY formatted_date DESC

这是我的表格数据：
用户列表

id    date_added
1     1234567890
2     1334567890
3     1434567890

用户链接

id    date_added
1     1244567890
2     1354567890
3     1464567890

提供广告

id    date_served    revenue
1     1234567891     0.01
2     1334567892     0.02
3     1434567893     0.02

行动

id    date_served
1     1234561890
2     1334562890
3     1434563890

我试图将ads-served表中格式化日期的收入作为输出查询的第6列相加。我不知道从哪里开始。如果将总和（收入）添加到union select中，则会出现“列不匹配”错误。

最佳答案

这样试试。为什么使用1=1？

SELECT
    FROM_UNIXTIME( date_added,  '%m-%d-%Y' ) AS formatted_date,
    SUM( tb =1 ) AS sum_users,
    SUM( tb =2 ) AS sum_links,
    SUM( tb =3 ) AS sum_ads,
    SUM( tb =4 ) AS sum_actions,
    sum(total) as tot_rev
FROM (
    SELECT date_added,'' as total, 1 AS tb
        FROM users_list WHERE 1=1
    UNION ALL
    SELECT date_added,'', 2
        FROM users_links WHERE 1=1
    UNION ALL
    SELECT date_served,revenue, 3
        FROM ads_served WHERE 1=1
    UNION ALL
    SELECT date_served,'', 4
        FROM actions WHERE 1=1
) AS t
GROUP BY formatted_date
ORDER BY formatted_date DESC

关于mysql - 联合选择列不匹配，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/5863677/