問題描述
我有一個表存儲，存儲有很多庫，在庫中我有存儲store_id的外鍵.
I have a table store, and store has many libraries, in library I have foreign key of store store_id.
存儲表
id(PK)
圖書館表
id(PK)
store_id(FK)
我對 hasMany 和 belongsTo 參數感到困惑，包括在 docs 它說
I'm confused with hasMany and belongsTo parameters include, in the docs it says
return $this->hasMany('AppComment', 'foreign_key');
return $this->hasMany('AppComment', 'foreign_key');
return $this->hasMany('AppComment', 'foreign_key', 'local_key');
return $this->hasMany('AppComment', 'foreign_key', 'local_key');
return $this->belongsTo('AppPost', 'foreign_key', 'other_key');
return $this->belongsTo('AppPost', 'foreign_key', 'other_key');
hasMany foreign_key 和 local_key 來自哪個表?和belongsTo一樣，foreign_key和other_key是從哪個表來的?
Which table of hasMany foreign_key and local_key came from? Same with belongsTo which table of foreign_key and other_key came from?
店鋪模式
public function library(){
return $this->hasMany('AppLibrary', 'what_foreign_key_should_be_here','what_other_key_should_be_here');
}
圖書館模型
public function stores(){
return $this->belongsTo('AppStores', 'what_foreign_key_should_be_here', 'what_other_key_should_be_here');
}
因為有時候我把一個表的主鍵id改成sid這樣的其他名字，所以我總是想指定哪個是外鍵和主鍵
Because sometimes I change my primary key id of a table to other name like sid, so I always want to specify which is foreign key and primary key
推薦答案
為了簡化語法，想到了 return $this->hasMany('AppComment', 'foreign_key', 'local_key'); 參數為:
To simplify the syntax, think of the return $this->hasMany('AppComment', 'foreign_key', 'local_key'); parameters as:
- 您要鏈接到的模型
- 鏈接回當前表的
id列的外部表(您要鏈接到的表)的列(除非您指定了第三個參數，在這種情況下它將使用那個) - 應該使用的當前表的列 - 即如果您不希望其他表的外鍵鏈接到當前表的
id列
- The model you want to link to
- The column of the foreign table (the table you are linking to) that links back to the
idcolumn of the current table (unless you are specifying the third parameter, in which case it will use that) - The column of the current table that should be used - i.e if you don't want the foreign key of the other table to link to the
idcolumn of the current table
在您的情況下，因為您在 libraries 表中使用了 store_id，您的生活變得輕松了.在您的 Store 模型中定義時，以下內容應該可以完美運行:
In your circumstance, because you have used store_id in the libraries table, you've made life easy for yourself. The below should work perfectly when defined in your Store model:
public function libraries()
{
return $this->hasMany('AppLibrary');
}
在幕后，Laravel 會自動將Store 表的id 列鏈接到Library<的store_id 列/code> 表格.
Behind the scenes, Laravel will automatically link the id column of the Store table to the store_id column of the Library table.
如果你想明確定義它，那么你可以這樣做:
If you wanted to explicitly define it, then you would do it like this:
public function libraries(){
return $this->hasMany('AppLibrary', 'store_id','id');
}
- 模型標準是單數命名的函數返回一個belongsTo，而復數函數返回一個hasMany(即
$store->libraries() 或$library->store()).
這篇關于Laravel hasMany 和belongsTo 參數的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！