Question

我希望能够在Category表中找到条件为visible = 0但不在下面的查询结果中的行：

SELECT c.id as cat_id, j.id
FROM category c
LEFT JOIN portfolio_job_category pjc
ON pjc.category_id = c.id
LEFT JOIN job j
ON j.id = pjc.job_id
WHERE c.visible = 0
AND j.end_date > CURRENT_DATE
GROUP BY c.id

有没有办法使用NOT IN来找到它？

我在下面试过，但这会永远循环并崩溃mysqld

SELECT c.id
FROM category c
WHERE c.id NOT IN
(SELECT c.id as cat_id, j.id
FROM category c
LEFT JOIN portfolio_job_category pjc
ON pjc.category_id = c.id
LEFT JOIN job j
ON j.id = pjc.job_id
WHERE c.visible = 0
AND j.end_date > CURRENT_DATE
GROUP BY c.id)
AND visible = 0

Answer 1

您尝试使用LEFT JOIN

SELECT  a.ID
FROM    category a
        LEFT JOIN
        (
            SELECT  c.id as cat_id
            FROM    category c
                    LEFT JOIN portfolio_job_category pjc
                        ON pjc.category_id = c.id
                    LEFT JOIN job j
                        ON j.id = pjc.job_id
            WHERE   c.visible = 0 AND 
                    j.end_date > CURRENT_DATE
        ) b ON a.ID = b.ID
WHERE   b.ID IS NULL AND
        a.visible = 0

MySQL使用NOT IN作为临时表

1 个答案: