Laravel 5.2 laravel如何对待这种归属关系? [英] Laravel 5.2 How laravel treat this belongsto relationship?

问题描述

我有3张桌子，下面列出了这些字段:

I have 3 tables, with the fields listed below:

价格

• id
• route_id

路线

• id
• from_city_id
• to_city_id

城市

• id
• 名称

到目前为止，字段之间的关系是:pricings belong to a route和routes belongs to city.

So far the relationships of fields are: pricings belong to a route, and routes belongs to city.

但是我不确定这些关系，因为from_city_id和to_city_id是与cities上的id相关的外键.

But I'm not sure about these relationships, since from_city_id and to_city_id are foreign keys relating to id on cities.

也许我在设计桌子或其他东西时错了.

Maybe I'm wrong designing my table or something else.

route_id是Routes表上id的外键. from_city_id和to_city_id是Cities表上id的外键.

route_id is a foreign key to id on the Routes table. from_city_id and to_city_id are foreign keys to id on the Cities table.

如何定义这3个表的关系，以便可以从定价模型(如$pricing->from_city->name和$pricing->to_city->name)获得from city name和to city name?

How I can define relationships of these 3 tables so I can get from city name and to city name from the pricings model, like $pricing->from_city->name and $pricing->to_city->name?

任何帮助表示赞赏.

更新:

我的定价模型:

public function route()
{
    return $this->belongsTo(Route::class);    
}

我的路线模型:

public function pricing(){
    return $this->hasOne(Pricing::class);    
}

public function zone(){
    return $this->belongsTo(Zone::class);    
}

public function city(){
    return $this->belongsTo(City::class);    
}

public function from_city(){
    return $this->belongsTo(City::class);    
}

public function to_city(){
    return $this->belongsTo(City::class);
}

现在我可以使用$pricing->route->from_city->name和$pricing->route->to_city->name

它显示了正确的结果，但是如何使用Laravel来实现呢?

It shows the correct result, but how can this be achieved using Laravel?

这是否意味着Laravel将假定route表具有字段to_city_id和from_city_id，因为路由模型中的方法是to_city()和from_city()?

Does this mean Laravel will assume that the route table has fields to_city_id and from_city_id, since the method in the route model is to_city() and from_city()?

谢谢

推荐答案

一种解决方案可能是进行迁移(新表或更改为现有表). https://laravel.com/docs/5.3/migrations

One solution may be to make a migration (new table or to change to existing table). https://laravel.com/docs/5.3/migrations

Laravel的模式构建非常方便: https://laravel.com/docs/5.0/schema

Laravel's schema build is super handy: https://laravel.com/docs/5.0/schema

routes迁移的示例为:

1. 进行迁移:

1. Make the migration:

php artisan make:迁移路线

php artisan make:migration routes

迁移看起来像:

```

使用Illuminate \ Database \ Schema \ Blueprint; 使用Illuminate \ Database \ Migrations \ Migration;

use Illuminate\Database\Schema\Blueprint; use Illuminate\Database\Migrations\Migration;

Class CreateUserRole扩展了迁移 { /** *运行迁移. * * @返回无效 */ 公共功能up() { Schema :: create('routes'，function(Blueprint $ table){

class CreateUserRole extends Migration { /** * Run the migrations. * * @return void */ public function up() { Schema::create('routes', function (Blueprint $table) {

        $table->increments('id');
        $table->foreign('id')->references('route_id')->on('pricings')->onDelete('cascade');

        $table->integer('from_city_id')->unsigned()->index();
        $table->foreign('from_city_id')->references('id')->on('cities')->onDelete('no action');             

        $table->integer('to_city_id')->unsigned()->index();
        $table->foreign('to_city_id')->references('id')->on('cities')->onDelete('no action');    

        $table->timestamps();

    });
}
/**
 * Reverse the migrations.
 *
 * @return void
 */
public function down()
{
    Schema::drop('routes');
}

}

```

以上内容由于某种原因无法在此处正确显示，因此这里是一个清理后的视图链接: http://viper-7.com/kfgUjt

The above for some reason will not show correctly on here, so here is a cleaned up view link: http://viper-7.com/kfgUjt

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