所以我知道如何使用JOIN创建查询,但是如何将这个JOIN变成子查询呢?我一直在尝试各种事情,但我无法弄清楚。
我的加入看起来像这样:
SELECT
c.email_address, o.order_id, o.order_date
FROM
customer c
JOIN orders o ON (c.customer_id = o.customer_id)
ORDER BY
order_date;
我创建多重表的尝试:
SELECT
c.email_address, o.order_id, o.order_date
FROM
customer c
WHERE
c.customer_id IN (SELECT o.customer_id FROM orders o)
ORDER BY
o.order_date;
对于unknown column
和order_id
,我总是收到order_date
的错误