通过使用 select has where 和 master 列来加入 mysql

Question

select t.* from 
    (
    SELECT p.*
    ,b.id as brand
    ,b.name as brandname
    ,j.id as closed
    ,c.name as customername
    ,l.name as productline
    ,u.user_name as username
    ,TIMESTAMPDIFF(HOUR,j1.start_date,j2.delivery_date) as total_hour
    
    FROM `project` AS p
    left join customer as c on c.id = p.customer
    left join brand as b on b.id = c.brand 
    left join customer_product_line as l on l.id = p.product_line
    left join users as u on u.id = p.created_by
    left join (select project_id,`status`,id from job where `status` <> '1' group by project_id,`status`) as j on j.project_id = p.id
    left join (select project_id,start_date  from job where project_id = id order by start_date asc limit 1) as j1 on j1.project_id = p.id
    left join (select project_id,delivery_date  from job  where project_id = id  order by delivery_date DESC limit 1) as j2 on j2.project_id = p.id
    
    ) t 

我在最后 2 个左连接中

p.id

有错误

任何通过函数或过程或其他方式来做到这一点的方法

Answer 1

您不能在

JOIN

中使用相关子查询。

无需在子查询中使用

ORDER BY <column> DESC LIMIT 1

，只需在其

MAX(<column>)

列表中使用

SELECT

即可。您可以使用单个查询来获取

MAX(start_date)

和

MAX(delivery_date)

。

SELECT p.*
    ,b.id as brand
    ,b.name as brandname
    ,j.id as closed
    ,c.name as customername
    ,l.name as productline
    ,u.user_name as username
    ,TIMESTAMPDIFF(HOUR,j1.max_start,j1.max_delivery) as total_hour
FROM `project` AS p
left join customer as c on c.id = p.customer
left join brand as b on b.id = c.brand 
left join customer_product_line as l on l.id = p.product_line
left join users as u on u.id = p.created_by
left join (select project_id,`status`,id from job where `status` <> '1' group by project_id,`status`) as j on j.project_id = p.id
left join (
    select project_id,MAX(start_date) AS max_start, MAX(delivery_date) AS max_delivery
    from job
    GROUP BY project_id
) as j1 on j1.project_id = p.id