Question

I have 2 tables stores and shares in a mysql database. I am trying to avoid an IN clause. Please see below for more details

select id, user_id from stores where user_id =7;
+----+---------+
| id | user_id |
+----+---------+
| 36 |       7 |
| 37 |       7 |


select stores_id,share_id from shares where share_id=7;
+-----------+----------+
| stores_id | share_id |
+-----------+----------+
|        15 |        7 |
|        38 |        7 |

Now I run this

SELECT stores.id
FROM   stores
WHERE  user_id = 7
UNION
(SELECT stores.id
 FROM   stores
 WHERE  id IN (SELECT stores_id
               FROM   shares
               WHERE  share_id = 7)); 

To get the below result:

+----+
| id |
+----+
| 36 |
| 37 |
| 15 |
| 38 |
+----+

QUESTION
How can I rewrite the query so that I don’t use the IN key word.?

Answer 1

This can help to you:

select stores.id from stores where user_id = 7  
UNION  
select s1.id from stores s1 
       inner join shares s2 
       on s2.share_id = 7 
       and s1.id = s2.stores_id;