按时间对同一张表上的多个计数查询进行分组

Question

我有一个查询，其中我需要 3 列以及一个额外的“时间”列，我需要做的是运行每个计数查询并将它们与相关的时间相匹配，但是发生的事情是查询是返回计数的总和并将它们添加到每次。见下文。

应该发生的事情是我得到一个这样的列表：

我知道这是我最后分组的方式，但我似乎无法在计数范围内分组，有人有什么想法吗？

SELECT
case 
when ( extract( HOUR FROM e.started) = 0 ) then '12am'
when ( extract( HOUR FROM e.started) < 12) then concat(extract(HOUR FROM e.started), 'am') 
when ( extract( HOUR FROM e.started) = 12) then '12pm'
when ( extract( HOUR FROM e.started) > 12) then concat( ( extract(HOUR FROM e.started) -12 ), 'pm') 
end  AS "Time", 
(
    SELECT COUNT(*)
    FROM eventinfo e
    join tickets o on e.ticket_id = o.id
    where e.created > '2018-02-20 00:00:00' and e.created < '2018-02-21 00:00:00'
        and o.stagename = ’Stage3'
) AS 'Column1',
(
    SELECT COUNT(*)
    FROM eventinfo e
    join tickets o on e.ticket_id = o.id
    where e.created > '2018-02-20 00:00:00' and e.created < '2018-02-21 00:00:00'
    and o.stagename = ’Stage2'

) AS 'Column2',
(
    SELECT COUNT(*)
    FROM eventinfo e
    join tickets o on e.ticket_id = o.id
    where e.created > '2018-02-20 00:00:00' and e.created < '2018-02-21 00:00:00'
    and o.stagename = ’Stage1'
) AS 'Column3'
FROM eventinfo e
group by extract(hour from e.started)

编辑： 如果我从每个计数查询中查询时间，我会收到错误：“操作数应包含 1 列”

    SELECT
(
    SELECT 
    case 
    when ( extract( HOUR FROM e.started_at) = 0 ) then '12am'
    when ( extract( HOUR FROM e.started_at) < 12) then concat(extract(HOUR FROM e.started_at), 'am') 
    when ( extract( HOUR FROM e.started_at) = 12) then '12pm'
    when ( extract( HOUR FROM e.started_at) > 12) then concat( ( extract(HOUR FROM e.started_at) -12 ), 'pm') 
    end  AS "Time", 
    COUNT(*)
    FROM events e
    join operations o on e.operation_id = o.id
where e.created_at > '2018-02-20 00:00:00' and e.created_at < '2018-02-21 00:00:00'
    and o.stagename = ’Stage1'
) AS 'Column1',
(
    SELECT 
    case 
    when ( extract( HOUR FROM e.started_at) = 0 ) then '12am'
    when ( extract( HOUR FROM e.started_at) < 12) then concat(extract(HOUR FROM e.started_at), 'am') 
    when ( extract( HOUR FROM e.started_at) = 12) then '12pm'
    when ( extract( HOUR FROM e.started_at) > 12) then concat( ( extract(HOUR FROM e.started_at) -12 ), 'pm') 
    end  AS "Time", 
    COUNT(*)
    FROM events e
    join operations o on e.operation_id = o.id
where e.created_at > '2018-02-20 00:00:00' and e.created_at < '2018-02-21 00:00:00'
    and o.stagename = ’Stage2'

) AS 'Column2',
(
    SELECT 
    case 
    when ( extract( HOUR FROM e.started_at) = 0 ) then '12am'
    when ( extract( HOUR FROM e.started_at) < 12) then concat(extract(HOUR FROM e.started_at), 'am') 
    when ( extract( HOUR FROM e.started_at) = 12) then '12pm'
    when ( extract( HOUR FROM e.started_at) > 12) then concat( ( extract(HOUR FROM e.started_at) -12 ), 'pm') 
    end  AS "Time", 
    COUNT(*)
    FROM events e
    join operations o on e.operation_id = o.id
    where e.created_at > '2018-02-20 00:00:00' and e.created_at < '2018-02-21 00:00:00'
    and o.stagename = ’Stage3'
) AS 'Column3'

Answer 1

您查询相同来源的次数过多。一切都可以在一次运行中完成。有关更具体的答案，请指定您正在使用的 RDBMS 以及有关所需输出的更多信息，因为您提供的信息显然不是查询的结果。

试试这个：

SELECT
CONCAT(TIME_FORMAT(e.started, "%h"), TIME_FORMAT(e.started, "%p")) AS "Time", 

sum(case when  o.stagename = 'Stage3' then 1 else 0 end) as 'Column1',
sum(case when  o.stagename = 'Stage2' then 1 else 0 end) AS 'Column2',
sum(case when  o.stagename = 'Stage1' then 1 else 0 end) AS 'Column3'

FROM eventinfo e
    join tickets o on e.ticket_id = o.id

group by extract(hour from e.started)