我有三个表：
类别：
|Id | TopId|
| 1 | null |
| 2 | null |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 3 |
等等...
类别文化：
|Id|CultureOf|CultureId|Name |
|1 | 1 | 1 |Category 1|
|2 | 1 | 2 |Klasse 1|
|3 | 1 | 3 |Kategori 1|
|4 | 2 | 1 |Category 2|
|5 | 2 | 2 |Klasse 2|
|6 | 2 | 3 |Kategori 2|
CultureOf也表示：CategoryId
等等...
文化：
|Id|Name|Flag |
|1 |en |/images/en.png|
|2 |de |/images/de.png|
|3 |tr |/images/tr.png|
和这个SQL脚本正在得到我所需要的，但没有空的顶部ID。
select c.Id as Id, cp.Id as TopId, cc.Name as Name, ccp.Name as TopName, cul.Id as CultureId, cul.Name as CultureName
from categories as c
inner join categories as cp on c.TopId = cp.Id
inner join categorycultures as cc on cc.CultureOf = c.Id
inner join categorycultures as ccp on ccp.CultureOf = cp.Id
inner join cultures as cul on cul.Id = cc.CultureId and cul.Id = ccp.CultureId
where cul.Id = 2
结果是：
缺少那些TopId为null的行
我已经尝试过很多情况，当针对cp的内部联接进行序列化并尝试了许多脚本时，却无法获得正确的值。
最佳答案
尝试这个
正确加入文化作为文化
关于mysql - MySQL查询与 parent 属性，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/47798917/