Question

这是我的第一个查询

SELECT DISTINCT(u.nickname) FROM user u 
                           where   u.id  IN(SELECT `submission_user`.`user_id` from `submission_user`) AND
                           u.member_since   >= '2015-07-01'

这是我的第二个查询

SELECT DISTINCT(u.nickname) FROM user u LEFT JOIN submission_user su ON su.user_id = u.id  
                            LEFT JOIN submission s ON s.id = su.submission_id
                             WHERE  s.date_time BETWEEN '2017-10-31' and '2018-07-31'

这是我的第三个查询

SELECT DISTINCT(u.nickname) FROM user u LEFT JOIN submission_user su ON su.user_id = u.id  
                            LEFT JOIN track_user tu ON tu.user_id = u.id
                            LEFT JOIN track ON track.id = tu.track_id                       
                            where track.uploaded_timestamp BETWEEN '2017-10-31' and '2018-07-31'

然后，我将第二和第三查询结果合并

 $ids_reactivated = array_unique(array_merge($track_user, $submit_user));

所以我的问题是，如果我想减去一个查询结果以将结果均值与（查询2和3）合并，即我的情况：$ ids_reactivated

任何人都有一个想法如何做... 我已经尝试了很多方法，并度过了一天...

希望人们能帮助我

Answer 1

感谢您的提示，但我得到了这样的答案...

   SELECT DISTINCT(u.nickname) FROM user u 
                               where   u.id  IN(SELECT `submission_user`.`user_id` from `submission_user`) AND
                               u.member_since   >= '2015-07-01' 
    **and u.nickname not in ($query2)**

UNION 
SELECT DISTINCT(u.nickname) FROM user u 
                               where   u.id  IN(SELECT `submission_user`.`user_id` from `submission_user`) AND
                               u.member_since   >= '2015-07-01' 
    **and u.nickname not in ($query3)**

Answer 2

很简单，您可以利用并集进行合并，而不能进行减法以下是示例

SELECT DISTINCT(u.nickname) FROM user u LEFT JOIN submission_user su ON su.user_id = u.id LEFT JOIN submission s ON s.id = su.submission_id
WHERE  s.date_time BETWEEN '2017-10-31' and '2018-07-31' 
**and u.nickname not in ($query1)**

UNION

SELECT DISTINCT(u.nickname) FROM user u LEFT JOIN submission_user su ON su.user_id = u.id LEFT JOIN track_user tu ON tu.user_id = u.id LEFT JOIN track ON track.id = tu.track_id 
where track.uploaded_timestamp BETWEEN '2017-10-31' and '2018-07-31' 
**and u.nickname not in ($query1)**

用查询更改$ query1，它应该给出结果

如何在MySQL中将一个查询结果减去另一个查询

2 个答案: