Question

我有SQL，它返回正确的结果。

select accounts.name, count( case when ((( estimated_start_date<='2013-01-01' 
and project.status='closed')

or ( estimated_start_date<='2013-01-01' and project.status='open' 
and estimated_end_date>='2013-04-01')))
then 1 else null end) as Number

from project

inner join project_cstm on project.id=project_cstm.id_c
inner join accounts on project_cstm.account_id_c=accounts.id

group by accounts.name

我给我的结果很好：

例如：

Telenor 5
Telecom 3

现在我想在BOOKED_DATE子句中添加新字段WHERE以限制项目数量，仅限于在该时间间隔内创建的某些项目任务。所以我用表inner join project_task进行INNER JOIN并且结果应该更小但是我得到的结果是这些巨大的数字。不知道如何组合它。

感谢您的帮助

Telenor 150
Telecom 980

select accounts.name, count( case when ((( estimated_start_date<='2013-01-01' 
and project.status='closed')

or ( estimated_start_date<='2013-01-01' and project.status='open' 
and estimated_end_date>='2013-04-01')))
then 1 else null end) as Number

from project

inner join project_cstm on project.id=project_cstm.id_c
inner join accounts on project_cstm.account_id_c=accounts.id
inner join project_task on project_task.project_id=project.id
where booked_date>'2013-01-01' and booked_date<'2015-01-01'
group by accounts.name

由于表PROJECT_TASK中的行，我得到了巨大的结果，这是远非正确的。如何限制？我尝试了... count(distinct case when ...，但结果总是为1。

所以我必须以某种方式限制这些值，而不是我

Answer 1

你为项目的每项任务计算1，这就是为什么你有这么多。
对于每个项目，您只需要增加一次计数。

你想计算不同的项目，所以不要只计算1，而是计算不同的项目ID：

select accounts.name
     , count( distinct  -- here distinct
        case when ((( estimated_start_date<='2013-01-01' and project.status='closed')
                 or ( estimated_start_date<='2013-01-01' and project.status='open' and estimated_end_date>='2013-04-01')))
        then project.id -- here project id
        else null 
        end) as Number
from project
    inner join project_cstm 
        on project.id=project_cstm.id_c
    inner join accounts 
        on project_cstm.account_id_c=accounts.id
    inner join project_task 
        on project_task.project_id=project.id
where booked_date>'2013-01-01' 
and booked_date<'2015-01-01'
group by accounts.name

Answer 2

我无法测试您的查询，但我认为您应该使用以下内容：

select accounts.name, count(DISTINCT project.id) as Number
from project   
  inner join project_cstm on project.id=project_cstm.id_c
  inner join accounts on project_cstm.account_id_c=accounts.id
  inner join project_task on project_task.project_id=project.id
where
  (booked_date>'2013-01-01' and booked_date<'2015-01-01')
  AND ((estimated_start_date<='2013-01-01' and project.status='closed')
      OR
       (estimated_start_date<='2013-01-01'
        and project.status='open'
        and estimated_end_date>='2013-04-01'))
group by accounts.name

Answer 3

您的加入表project_task可能在“project_id”列中有重复项

SQL - 结合DISTINCT和INNER JOIN以及COUNT（CASE WHEN）

3 个答案: