Laravel 实现属于一个或某个类别的一个产品

Question

在我的数据库中，我有 product_category 和 products 一个 product 可能属于 product_category 表中的一个或某个类别，现在我的问题是：当用户提交具有一个或某个类别的产品时，如何我将其保存在数据库中，例如一个类别有一种或某种产品？

在视图中我有多个选择：

{{ Form::select('categories[]', $productCategories, null, array('class' => 'multiselect-success multiselect_selected','multiple'=>'multiple')) }} 

products模特：

class Products extends Model
{
    protected $table = 'products';
    protected $guarded = ['id'];
    protected $casts = [
        'images' => 'array'
    ];

    public function productCategories()
    {
        return $this->belongsTo(ProductCategories::class);
    }
}

productCategories模特：

class ProductCategories extends Model
{
    protected $table = 'product_categories';
    protected $guarded =['id'];
    protected $casts=[
        'images'=>'array'
    ];

    public function products()
    {
        return $this->hasMany(Products::class);
    }
}

和store 函数转换成controller：

public function store(RequestProducts $request)
{
    try {
        $data = Products::create([
            'name' => $request->name,
            'amount' => $request->amount,
            'product_code' => $request->product_code,
            'weight' => $request->weight
            /* MY PROBLEM IS HERE */
            'category_id' => $request->categories
        ]);
    } catch (Exception $ex) {
        ...
    }

    return redirect(route('manageProductCategories.index'));
}

在 html 视图中 categories 是一个数组，我该如何实现它？

更新

使用createMany 更新代码后，我收到此错误：

General error: 1364 Field 'category_id' doesn't have a default value (SQL: insert into `products` (`name`, `lang`, `amount`, `product_code`, `weight`, `images`, `updated_at`, `created_at`) values (eqweqwe, fa, 45,000, asd, asdasd, '', 2017-12-09 04:45:44, 2017-12-09 04:45:44))

迁移文件：

public function up()
{
    Schema::create('product_categories', function (Blueprint $table) {
        $table->increments('id');
        $table->string('category_name');
        $table->string('lang', 2);
        $table->text('images');
        $table->timestamps();
    });
}

public function up()
{
    Schema::create('products', function (Blueprint $table) {
        $table->increments('id');
        $table->string('name');
        $table->string('amount');
        $table->string('product_code');
        $table->string('weight');
        $table->string('lang', 2);
        $table->text('images');
        $table->integer('category_id')->unsigned()->index();
        $table->foreign('category_id')->references('id')->on('product_categories')->onDelete('cascade');
        $table->timestamps();
    });
}

Answer 1

从你的问题和cmets，我理解以下内容。

许多产品可能有类别“category_1”，而“product_1”可能属于许多类别。

要实现这一点，您必须使用“多对多”关系。 我已经更新了你的代码，这可能会对你有所帮助。

迁移：

public function up()
{
    Schema::create('product_categories', function (Blueprint $table) {
        $table->increments('id');
        $table->string('category_name');
        $table->string('lang', 2);
        $table->text('images');
        $table->timestamps();
    });
}

public function up()
{
    Schema::create('products', function (Blueprint $table) {
        $table->increments('id');
        $table->string('name');
        $table->string('amount');
        $table->string('product_code');
        $table->string('weight');
        $table->string('lang', 2);
        $table->text('images');
        $table->timestamps();
    });
}
    public function up()
{
    Schema::create('products_product_category', function (Blueprint $table) {
        $table->integer('product_id');
        $table->integer('product_category_id');
    });
}

模型

产品型号：

class Products extends Model
{
    protected $table = 'products';
    protected $guarded = ['id'];
    protected $casts = [
        'images' => 'array'
    ];

    public function productCategories()
    {
        return $this->belongsToMany(ProductCategories::class,'products_product_category');
    }
}

productCategories 型号：

class ProductCategories extends Model
{
    protected $table = 'product_categories';
    protected $guarded =['id'];
    protected $casts=[
        'images'=>'array'
    ];

    public function products()
    {
        return $this->belongsToMany(Products::class, 'products_product_category');
    }
}

控制器

public function store(RequestProducts $request)
{
    try {
        $data = Products::create([
            'name' => $request->name,
            'amount' => $request->amount,
            'product_code' => $request->product_code,
            'weight' => $request->weight
        ]);
        $data->productCategories()->sync($request->categories);
    } catch (Exception $ex) {
        ...
    }

    return redirect(route('manageProductCategories.index'));
}

希望它会有所帮助..