如何使用三个表编写这个复杂的MySQL查询？

任务表 - TASK_ID，ACTIVITY_ID（外键），日期，结束日期
活动表 - ACTIVITY_ID，milestone_id（外键），other_fields
里程碑表 - milestone_id，PROJECT_ID，other_fields

现在我想结果S et像这样

No_of_task(count) | no_activity | milestone_name 
     5   :  2  : ABC Milestone

我想统计end_dated任务，根据end_date任务和里程碑名称计数活动。

例如，1里程碑，有5个活动，20个不同的任务名称Housing_Construction ...一些任务end_dated所以

5任务结束这样housing_construction的3活性。

任务表的说明

+-----------------------+-------------+------+-----+---------+----------------+ 
| Field     | Type  | Null | Key | Default | Extra   | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| activity_task_id  | int(11)  | NO | PRI | NULL | auto_increment | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| milestone_activity_id | int(11)  | YES | MUL | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| task     | varchar(50) | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| description   | text  | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| assign_to_employee_id | int(11)  | YES | MUL | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| assign_date   | datetime | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| task_end_date   | date  | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| tasktime    | varchar(50) | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| status    | tinyint(1) | YES |  | 0  |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| is_delete    | tinyint(1) | YES |  | 0  |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| entry_employee_id  | int(11)  | YES | MUL | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| edit_employee_id  | int(11)  | YES | MUL | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| createddatetime  | datetime | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| modifydatetime  | datetime | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| nooftimesedit   | smallint(6) | YES |  | 0  |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| completion_date  | datetime | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+

ActivityTable描述

+-----------------------+-------------+------+-----+---------+----------------+ 
| Field     | Type  | Null | Key | Default | Extra   | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| milestone_activity_id | int(11)  | NO | PRI | NULL | auto_increment | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| project_milestone_id | int(11)  | YES | MUL | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| activityname   | varchar(50) | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| activity_end_date  | date  | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| activity_description | text  | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| status    | tinyint(1) | YES |  | 0  |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| is_delete    | tinyint(1) | YES |  | 0  |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| entry_employee_id  | int(11)  | YES | MUL | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| edit_employee_id  | int(11)  | YES | MUL | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| createddatetime  | datetime | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| modifydatetime  | datetime | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| nooftimesedit   | smallint(6) | YES |  | 0  |    | 
+-----------------------+-------------+------+-----+---------+----------------+

表里程碑描述

+-----------------------+-------------+------+-----+---------+----------------+ 
| Field     | Type  | Null | Key | Default | Extra   | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| project_milestone_id | int(11)  | NO | PRI | NULL | auto_increment | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| project_id   | int(11)  | YES | MUL | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| milestone    | varchar(50) | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| milestone_description | text  | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| milestone_end_date | date  | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| status    | tinyint(1) | YES |  | 0  |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| is_delete    | tinyint(1) | YES |  | 0  |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| entry_employee_id  | int(11)  | YES | MUL | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| edit_employee_id  | int(11)  | YES | MUL | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| createddatetime  | datetime | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| modifydatetime  | datetime | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| nooftimesedit   | smallint(6) | YES |  | 0  |    | 
+-----------------------+-------------+------+-----+---------+----------------+ 
| noofdays    | int(11)  | YES |  | NULL |    | 
+-----------------------+-------------+------+-----+---------+----------------+

来源

2016-12-27 Hardik

试试这个：

select 
    count(distinct t.activity_task_id) No_of_task, 
    count(distinct a.milestone_activity_id) no_activity, 
    m.milestone_description milestone_name 
from milestone m 
inner join activity a 
    on m.project_milestone_id = a.project_milestone_id 
inner join task t 
    on a.milestone_activity_id = t.milestone_activity_id 
where t.status != 4 
and t.task_end_date < curdate() 
group by m.project_milestone_id, 
    m.milestone_description;

来源

2016-12-27 05:31:54 GurV

感谢评论，但放在哪里结束日期条件在此查询？ – Hardik

select t.count as No_of_task from （SELECT COUNT（activity_task_id）count from activity_task_details where status！= 4 and task_end_date Hardik

@hardik请参阅已更新的答案't.end_date' – GurV

可以使用JOIN为了这个目的，使用此下面的代码，

SELECT COUNT(T.task_id) as no_of_task, 
     COUNT(A.activity_id) as no_of_activity, 
     MAX(M.milestone_name) as milestone_name 
FROM milestone M 
INNER JOIN activity A on M.milestone_id=A.milestone_id 
INNER JOIN task T on T.activity_id =A.activity_id 
GROUP BY A.activity_id,T.task_id 
HAVING T.end_date < curdate()

来源

2016-12-27 05:32:02

谢谢你的回复，我会试试这个，但是在哪里可以放置过时的任务？在任务开始日期和结束日期中有两个字段，我需要在'GROUP BY'之后结束 – Hardik

的任务计数，您可以像这样放置'HAVING [value1] = 1' –

select t.count as No_of_task from （ SELECT COUNT（activity_task_id）count from activity_task_details where status！= 4 and task_end_date Hardik

如何使用三个表编写这个复杂的MySQL查询？

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