Question

我需要一些帮助来解决查询问题。我想加入两个select语句的输出：

第一

select extract(year from createdDate) as year,
       count(extract(year from createdDate)) as count
from table
where to_user_id= 322
group by extract(year from createdDate);

及其输出

Year    Count
2014    18
2015    117
2016    9

和第二次查询

select count(extract(year from createdDate)) as count
from table
where userId=322
group by extract(year from createdDate);

及其输出

我想将这两个表添加到一个表中。我想要那种类型的输出，

Year    Count Count
2014    18     18
2015    117    110
2016    9      11

请注意，我在查询1中使用to_user_id，但在查询2中使用userId。

我试图解决这个问题，但我在输出中得到了重复的值。有人知道解决方案吗？

Answer 1

将它们写为子查询并将它们连接在一起。

SELECT a.year, a.count AS t_user_count, b.count AS user_count
FROM (select YEAR(create_date) AS year, COUNT(*) AS count
      FROM table
      WHERE to_user_id = 322
      GROUP BY year) AS a
JOIN (SELECT YEAR(create_date) AS year, COUNT(*) AS count
      FROM table
      WHERE user_id = 322
      GROUP BY year) AS b
ON a.year = b.year

我需要在mysql中加入两个表

1 个答案: