Question

你好团队是sql的新手

我有两个像这样的选择查询

select fv.value as primary_hod, count(*) as closed
from artifact a, item i, field_value fv
where i.id=a.id and i.folder_id = 'tracker1127' and fv.id = a.fv_0
  and a.close_date is not NULL  and i.date_created > i.date_created - INTERVAL '30 days'
group by fv.value;

这是返回

 primary_hod    | closed
------------------+--------
 Sivaramakrishnan |      1

和其他查询

select fv.value as primary_hod, count(*) as Open
from artifact a, item i, field_value fv
where i.id=a.id and i.folder_id = 'tracker1127' and fv.id=a.fv_0
  and a.close_date is NULL and i.date_created > i.date_created - INTERVAL '30 days'
group by fv.value;

返回

   primary_hod    | open
------------------+------
 Sivaramakrishnan |    1
 Anand            |    2
 Manav            |    1
 Prasanna         |    1

我想要这样的东西

  primary_hod    | open | Closed
------------------+------+
 Sivaramakrishnan |    1 | 1
 Anand            |    2 | 0
 Manav            |    1 | 0
 Prasanna         |    1 | 0

我尝试过工会和工会，但没有运气请注意这个

Answer 1

使用CASE表达式进行条件计数：

select fv.value as primary_hod,
       count(case when a.close_date is NULL then 1 end) as open,
       count(case when a.close_date is not NULL then 1 end) as closed
from artifact a, item i, field_value fv
where i.id=a.id and i.folder_id = 'tracker1127' and fv.id = a.fv_0
  and i.date_created > i.date_created - INTERVAL '30 days'
group by fv.value;

使用现代明确的JOIN语法重写：

select fv.value as primary_hod,
       count(case when a.close_date is NULL then 1 end) as open,
       count(case when a.close_date is not NULL then 1 end) as closed
from artifact a
  join item i on i.id = a.id
  join field_value fv on fv.id = a.fv_0
where i.folder_id = 'tracker1127' 
  and i.date_created > i.date_created - INTERVAL '30 days'
group by fv.value;

Answer 2

您可以在子查询中嵌套一个。

SELECT fv.value AS primary_hod, count(*) AS Open, (SELECT count(*) FROM artifact a
INNER JOIN item i ON i.id = a.id 
INNER JOIN field_value fv ON fv.id = a.fv_0 
WHERE i.folder_id = 'tracker1127' 
AND a.close_date IS NOT NULL  
AND i.date_created > i.date_created - INTERVAL '30 days' 
GROUP BY fv.value) AS Closed
FROM artifact a
INNER JOIN item i ON i.id = a.id 
INNER JOIN field_value fv ON fv.id = a.fv_0 
WHERE i.folder_id = 'tracker1127' 
AND a.close_date IS NULL  
AND i.date_created > i.date_created - INTERVAL '30 days' 
GROUP BY fv.value;

合并两个选择查询，如果没有值，则将零添加到列

2 个答案: