在三级子查询中获取父列

Question

如何从子查询中的子查询中最顶端的父查询中获取列？我必须像传递变量一样传递它吗？这是我的代码：

SELECT c.in_customer_id, 
( 
SELECT
group_concat(the_schedule separator 'rn') 
FROM
( 
SELECT
concat_ws('n', 'Route: ', s.route_id, 'Interval: ', s.service_interval, 'Week No.: ', s.week_no, 'Weekdays: ', s.weekdays, 'Start Date: ', s.start_date, 'End Date: ', s.end_date, 'Start Time: ', s.start_time, 'End Time: ', s.end_time, 'n') AS the_schedule
FROM
schedule s 
WHERE
s.service_address_id IN 
( 
SELECT in_customer_address_id 
FROM   tbl_customer_address a2 
WHERE  a2.in_customer_id = c.in_customer_id
) 
AND s.is_skipped = '0'
GROUP BY
s.service_address_id
) a
)
AS "Schedule"
FROM
tbl_customers c

我得到的回复是"错误代码：1054。"where clause"中的未知列"c.in_customer_id">

Answer 1

原则上，您希望将子查询移到FROM子句中。

试试这样的。。。

SELECT
c.in_customer_id,
s.grouped_schedule
FROM
tbl_customers   AS c
LEFT JOIN
(
SELECT
in_customer_id,
group_concat(the_schedule separator 'rn') AS grouped_schedule
FROM
(
SELECT
a.in_customer_id,
a.in_customer_address_id,
concat_ws('n', 'Route: ', s.route_id, 'Interval: ', s.service_interval, 'Week No.: ', s.week_no, 'Weekdays: ', s.weekdays, 'Start Date: ', s.start_date, 'End Date: ', s.end_date, 'Start Time: ', s.start_time, 'End Time: ', s.end_time, 'n') AS the_schedule
FROM
tbl_customer_address  AS a
INNER JOIN
schedule              AS s
ON s.service_address_id = a.in_customer_address_id
WHERE
s.is_skipped = 0
)
AS schedules
GROUP BY
in_cusomer_id
)
AS s
ON s.in_customer_id = c.in_customer_id