Question

我有两个表：jobs和job_industries（加入jobs.id=job_industries.job_id）。我想找到jobs.title like '%Finance%'而没有job_industries.industry=1的所有工作。

但是，在运行下面的查询时，我会获得与标题条件匹配的每个作业的列表，并且至少有一个行业选项不是1。

select jobs.id, title, industry
from `job_industries`
left join jobs on jobs.id=`job_industries`.job_id
where is_live=1 and jobs.`is_closed`=0 and 1 in (select industry from job_industries where job_id in )

e.g。如果作业有两个job_industry关系（industry=1和industry=2），则此作业将与查询匹配。我宁愿找到那些没有的工作。

Answer 1

SELECT j.id, j.title, ji.industry
    FROM jobs j
        INNER JOIN job_industries ji
            ON j.id = ji.job_id
                AND ji.industry <> 1
    WHERE j.title LIKE '%Finance%'
        AND j.is_live = 1
        AND j.is_closed = 0
        AND NOT EXISTS (SELECT 1
                            FROM job_industries ji2
                            WHERE ji2.job_id = j.id
                                AND ji2.industry = 1);

或者，你可以这样做：

SELECT j.id, j.title, ji.industry
    FROM jobs j
        INNER JOIN job_industries ji
            ON j.id = ji.job_id
                AND ji.industry <> 1
        LEFT JOIN job_industries ji2
            ON j.id = ji2.job_id
                AND ji2.industry = 1
    WHERE j.title LIKE '%Finance%'
        AND j.is_live = 1
        AND j.is_closed = 0
        AND ji2.job_id IS NULL;

Answer 2

select jobs.id, title, industry
from `job_industries`
left join jobs on jobs.id=`job_industries`.job_id AND job_industries.industry=1
where is_live=1 and jobs.`is_closed`=0 and job_industries.industry IS NULL

过滤一对多关系的多方面

2 个答案: