这是桌子
mysql> desc tags;
+------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| content_id | int(11) | NO | | NULL | |
| name | varchar(100) | NO | | NULL | |
+------------+--------------+------+-----+---------+----------------+
3 rows in set (0.00 sec)
一些数据
mysql> select * from tags;
+----+------------+---------------+
| id | content_id | name |
+----+------------+---------------+
| 1 | 36 | banana |
| 2 | 36 | strawberry |
| 3 | 36 | orange |
| 4 | 36 | apple |
| 5 | 36 | watermelon |
| 6 | 37 | qiwi |
| 7 | 37 | apple |
| 8 | 37 | orange |
| 9 | 37 | bed |
| 10 | 38 | grape |
| 11 | 38 | apple |
+----+------------+---------------+
11 rows in set (0.00 sec)
我想要的是获取唯一的
content_id
列表,其中的name
是苹果,而content_id还具有与之关联的ORANGE。因此,在此示例中,如果我想知道同时用“ apple”和“ orange”标记了哪些content_id,则会导致:
+------------+
| content_id |
+------------+
| 36 |
| 37 |
+------------+
因为只有这两个content_id被相应地标记了。最好的方法是什么?
最佳答案
select content_id
from tags
where `name` in ('banana', 'orange')
group by content_id
having count(distinct `name`) >= 2