如何连接Car_type、Model和Mark Car Laravel mysql

Question

我有一款车，牌子和型号表。当用户选择汽车类型时，他会得到奥迪、宝马、梅赛德斯。在选择奥迪时，它只获得奥迪etc A1，A2，A3的车型。如果宝马赢得X6，X4车型。我有三张桌子1.打字和汽车。(目前唯一的汽车可能是自行车) 2.马克3.模型

如何将这三个表与Laravel eloquent连接起来？

Answer 1

--- car_types ---
id        name
1         sedan
2         hatchback
3         sport
4         suv

-- car_brands ---
id        name
1         bmw
2         mercedes
3         audi

-- car_models --
id        brand_id    model_name  car_type
1         3           A1          1
2         3           A2          1
3         3           A3          1
4         3           Q7          4
5         1           X5          4
6         1           X6          4
7         1           X7          4
8         2           AMG         3
9         3           A1          2


-- cars --
id model_id brand_id model_year name             ...other fields
1  1        3        2018       Audi A1 1.0 2018
2  3        3        2017       Audi A3 1.6 2017

on cars table brand_id* is optional foreign key as shortcut for reaching car's brand.

关系：

1. A汽车类型hasMany汽车型号。(国外:品牌> car_types.id)
2. A Car car_models.car_type hasMany Car Models.( car_brands.id)
3. A : car_models.brand_id > Car belongsToA Car Model.(国外: cars.model_id > car_models.id)
4. A Car belongsTo A Car Brand.(外部: car_brands.id)

> cars.brand_id

Answer 2

假设你有一个模型

CarType for Cars Types表CarBrand for car_brands表和CarModel car_models表

您可以使用Eloquent: Relationships来实现这一点

在CarType模型中

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class CarType extends Model
  {
    /**
     * Get the brands for the car .
     */
    public function brands()
  {
    return $this->hasMany('App\CarBrand');
  }
}

在您的CarBrand模型中，您可以使用以下命令获取品牌所属的汽车类型

<?php

 namespace App;

 use Illuminate\Database\Eloquent\Model;

 class CarBrand extends Model
 {
   /**
   * Get the car that owns the brand.
   */
  public function carType()
  {
    return $this->belongsTo('App\CarType');
  }
}

例如，您可以这样做

$car = Car->find(1); // to get car with ID 1.
$brands = $car->brands; // brands of the selected car. You can loop through now

此外，对于品牌，您可以这样做

$brand = Brand->find(1) // For Brand ID 1
$car = $brand->carType;

你可以查看Eloquent Relationships