Laravel：产品、类别和子类别！（关系船）
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Laravel: Products,Categories and SubCategories! (Relation ships)
提问by Someb
I have a problem! I make something but, not work so i will ask u for help! So the problem is
我有个问题！我做了一些东西，但不起作用，所以我会向你寻求帮助！所以问题是
I have this tables
我有这张桌子
products:
name,subcategory_id,category_id,price,description
Categories:
name,slug,timestamps
SubCategories:
name,slug,timestamps
I want to make when smo call this url /category/{category}/{subcategory}to get all products of subcategory are called! But when product don't have sub category to open only category , i mean /category/{category}
我想当smo调用这个url/category/{category}/{subcategory}来获取子类别的所有产品被调用！但是当产品没有子类别只能打开类别时，我的意思是/category/{category}
Thanks guys!
谢谢你们！
回答by Someb
Here i may help u with this!
在这里我可以帮助你！
First , you can use only one table for categories and subcategory!
首先，类别和子类别只能使用一个表！
You can make this:
你可以这样做：
|---------------------------------------
|id| |parent_id| |name| |slug|
|1 | | (NULL) | Electronics | electronics
|2 | | 1 | Phones | phones
Now category electronic have children Phones
现在品类电子有孩子 Phones
So in your Category.phpmodel u can make that
所以在你的Category.php模型中你可以做到
/**
* @return \Illuminate\Database\Eloquent\Relations\BelongsTo
*/
public function parent() {
return $this->belongsTo(self::class, 'parent_id');
}
/**
* @return \Illuminate\Database\Eloquent\Relations\HasMany
*/
public function children() {
return $this->hasMany(self::class, 'parent_id','id');
}
Now u can use foreach to display your children and category! Hope that helpful! ;)
现在您可以使用 foreach 来显示您的孩子和类别！希望有帮助！;)
回答by Rafa? Sardaw
It's classic problem related with databases You should use hierarchical child/parent relation. At first Your design of database is bad, just add one column with root category which has "0" in PARENT_ID.
这是与数据库相关的经典问题您应该使用分层的子/父关系。一开始你的数据库设计很糟糕，只需添加一个根类别在PARENT_ID中为“0”的列。
CREATE TABLE CATEGORIES (
CATEGORY_ID NUMBER,
PARENT_ID NUMBER,
NAME VARCHAR(255),
CREATE_TS TIMESTAMP(0));
and then read this : http://mikehillyer.com/articles/managing-hierarchical-data-in-mysql/& How to create a MySQL hierarchical recursive query& Bear in mind that You are mixing logic of GUI with SQL role. If You want to return in single query then Your presentation layer will be quite ugly ;-)
然后阅读此内容：http: //mikehillyer.com/articles/managing-hierarchical-data-in-mysql/& 如何创建 MySQL 分层递归查询& 请记住，您正在将 GUI 逻辑与 SQL 角色混合。如果您想在单个查询中返回，那么您的表示层将非常难看 ;-)
and also think about leaving just category_id in product table, if You have only 2 or 3 levels You don't need to point to subcategory and category.
并考虑在产品表中只留下 category_id，如果您只有 2 或 3 个级别，则不需要指向子类别和类别。
回答by Purvesh
I have done it as @rafalwardas said. Take a look at this my migration file.
我已经按照@rafalwardas 所说的做了。看看这个我的迁移文件。
here is my Eloquent model:
这是我的雄辩模型：
https://github.com/avored/framework/blob/master/src/Models/Database/Category.php
https://github.com/avored/framework/blob/master/src/Models/Database/Category.php
