Question

我有两张表格如下

user_job_applied

company_viewed_user

我想在user_job_applied表中获取不在company_viewed_user表中的相关job_id的行。我为它编写了以下查询，但没有抓住

SELECT
    `user_job_applied`.user_id
FROM
    `user_job_applied`
LEFT JOIN 
    `company_viewed_user` 
ON 
    `company_viewed_user`.user_id ON `company_viewed_user`.user_id = `user_job_applied`.user_id                               
WHERE
    `company_viewed_user`.user_id IS NULL AND
    `company_viewed_user`.emp_id IN (SELECT user_id 
                                     FROM company_user 
                                     WHERE company_id='1') 
AND
    `user_job_applied`.job_id = '1';

输出应如下所示

Answer 1

您可以使用以下查询

SELECT uja.user_id 
FROM `user_job_applied` AS uja 
LEFT JOIN `company_viewed_user` AS cvu ON cvu.user_id = uja.user_id                             
WHERE cvu.user_id IS NULL;

如果您想添加任何其他过滤器，那么您可以加入自己的过滤器或让我知道。

添加新条件

SELECT uja.user_id 
FROM `user_job_applied` AS uja 
JOIN company_user AS cu ON cu.user_id=uja.emp_id 
LEFT JOIN `company_viewed_user` AS cvu ON cvu.user_id = uja.user_id                             
WHERE uja.job_id=1 AND cu.company_id=1 AND cvu.user_id IS NULL;

注意：如果job_id和company_id不是Int类型，则用引号括起来。

Answer 2

希望将emp_id条件移动到where子句

中的左连接语句

SELECT
`user_job_applied`.user_id
FROM
`user_job_applied`
LEFT JOIN `company_viewed_user` ON `company_viewed_user`.user_id = `user_job_applied`.user_id AND 
                                                                `company_viewed_user`.emp_id IN (SELECT user_id FROM company_user WHERE company_id='1')                             
WHERE
`company_viewed_user`.user_id IS NULL AND                        
`user_job_applied`.job_id = '1';

如何在mysql中从连接表中获取不相等的行？

2 个答案: