在我的网站上，我有一种方法允许登录用户将文章标记为收藏夹，当登录时，文章会突出显示为保存为收藏夹，但是如果用户没有收藏夹，我无法获得查询返回任何数据，我的查询有什么问题？
SELECT `job_id`,
COUNT(jobs.job_id) as jobs,
`employers`.`employer_id`,
`logo_small`, `logo_large`,
`company_name`, `job_tags`,
`favourite_employers`.`employer_id` AS employer
FROM (`employers`)
LEFT JOIN `jobs` ON `employers`.`employer_id` = `jobs`.`employer_id`
JOIN `favourite_employers` ON `favourite_employers`.`employer_id` = `jobs`.`employer_id`
WHERE `favourite_employers`.`user_id` = '2'
GROUP BY `jobs`.`employer_id`
ORDER BY `jobs`.`job_id` DESC
最佳答案
对 favourite_employers 表使用 LEFT JOIN 而不是 JOIN
关于mysql 帮助...返回数据时遇到问题，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/6443871/