Question

分类db

id name    parent_id  slug
----------------------------------
1  Men     0          men
2  Shoes   1          shoes
3  Sports  2          sports
4  Women   0          women
5  Shoes   4          shoes
6  Sports  5          sports

假设我在domain/category/men/shoes/sports

$last_slug = end((explode('/', Request::url())));

在这里，我可以将sports作为最后一次查询

问题：

如何检索所有父母slug 动态，所以如果slu depth = 3我可以选择这样的东西？

SELECT t1.name AS level_one,
       t2.name AS level_two,
       t3.name AS level_three,
       t3.id   AS requested_id
FROM   categories AS t1
       LEFT JOIN categories AS t2 ON t2.parent_id = t1.id
       LEFT JOIN categories AS t3 ON t3.parent_id = t2.id
WHERE  t1.slug = 'men'
       AND t2.slug = 'shoes'
       AND t3.slug = 'sports'
LIMIT  1

Answer 1

最好的方法是在其他列中存储完整路径。

这是在db - Materialized Path中存储树的标准方法之一。

作为奖励，您可以通过单个查询选择当前类别的所有子项。

当slug更改或子类别从一个父级移动到另一个父级时，正确更新路径会更加棘手。但这种行动不会经常发生。

使用连接动态构建查询对性能不利，尤其是对于这样一个简单的任务：按路径选择类别。

Answer 2

只需在触摸周围交换连接顺序： -

SELECT t1.name AS level_one,
       t2.name AS level_two,
       t3.name AS level_three,
       t1.id   AS requested_id
FROM   categories AS t1
       LEFT JOIN categories AS t2 ON t2.id = t1.parent_id
       LEFT JOIN categories AS t3 ON t3.id = t2.parent_id
WHERE  t1.slug = 'sports'

如何从url中查找slug名称并创建动态查询语句

2 个答案: