Question

我在获取外键时遇到了一些麻烦。

我的迁移看起来像这样（缩短了它们）：

    <?php

    class CreateProductsTable extends Migration
    {
        public function up()
        {


    Schema::create('products', function (Blueprint $table) {
            $table->increments('id');
            $table->string('email');
            $table->string('title');
            $table->string('filename');
            $table->integer('number_of_chapters');
            $table->text('input_mpg');
            $table->timestamps();
        });
    }

    public function down()
    {
        Schema::drop('products');
    }
}

<?php

    class CreateChaptersTable extends Migration
    {

        public function up()
        {
            Schema::create('chapters', function (Blueprint $table) {
                $table->increments('id');
                $table->integer('product_id')->unsigned();   
                $table->time('input-chapter-start1');
                $table->time('input-chapter-end1');
                $table->timestamps();

            });

            Schema::table('chapters', function($table) {
                $table->foreign('product_id')->references('id')->on('products');
            });
        }

        public function down()
        {
            Schema::drop('chapters');
        }
    }

我的2模型是这样的：

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Chapters extends Model
{

    protected $table = 'chapters';

    protected $fillable = ['input-chapter-start1', 'input-chapter-end1'];

    public function product()
    {
        return $this->belongsTo('App\Product');
    }

}
<?php

    namespace App;

    use Illuminate\Database\Eloquent\Model;

    class Product extends Model
    {

        protected $table = 'products';

        protected $fillable = ['email', 'title', 'filename', 'inputMpg', 'number_of_chapters'];

        public static $rules = [
            'email'                => 'required|email|max:50',
            'title'                => 'required|max:50',
            'filename'             => 'required|max:50',
            'input_mpg'            => 'required'
        ];

        public function Chapters()
        {
            return $this->hasMany('App\Chapters');
        }

    }

只需将它保存在我的控制器中

$product->save();
$Chapters->save();

并收到以下错误：

SQLSTATE [23000]：完整性约束违规：1452无法添加或更新子行：外键约束失败（generator。chapters，CONSTRAINT chapters_product_id_foreign FOREIGN KEY（product_id）REFERENCES products（id））（SQL：insert 进入chapters（input-chapter-start1，input-chapter-end1， updated_at，created_at）值（12：12：12,12：12：12,2016-04-25 11：41：31,2016-04-25 11:41:31））

修改控制器看起来像这样：

namespace App\Http\Controllers;


class ProductController extends Controller
{

    protected $request;

    public function request(Request $request)
    {
        $this->request = $request;
    }

    public function createProduct(Request $request)
    {

        $product        = new Product;
        $Chapters       = new Chapters($request->all());

        $data              = $request->all();
        $projectEmail      = $request->input('email');
        $projectTitle      = $request->input('title');
        $projectFile       = $request->input('filename');
        $projectChapters   = $request->input('number_of_chapters');

        $validator = Validator::make($request->all(), Product::$rules);

        if($validator->fails())
        {
            return Redirect::back()->withInput()->withErrors($validator);
        }

        $product->fill($data);

        if($product->save())
        {

            $Chapters->product()->associate($product);
            $Chapters->save();
            return redirect()->route('root')->with('message', 'success')->withInput();
        }
        else
        {
            return redirect()->route('newProduct')->with('message', 'Error')->withInput();
        }

    }

}

编辑我试过Samsquanch建议：并在我的控制器中添加了这个：

$product->save();

$Chapters->product()->associate($product);

$Chapters->save();

但仍然收到此错误消息：

Builder.php第2093行中的BadMethodCallException：调用undefined 方法Illuminate \ Database \ Query \ Builder :: products（）

Answer 1

问题在于你没有告诉Laravel或MySQL应该是什么外键。

这里有两个选项（均来自文档：https://laravel.com/docs/5.1/eloquent-relationships#inserting-related-models）

第一个选项是将chapters保存到product：

$chapters = $product->chapters()->saveMany($Chapters); // or just->save() if it's only one

第二个（以及我通常如何做）将使用依赖于章节模型中associate()关系的belongsTo：

$product->save();

$Chapters->product()->associate($product);

$Chapters->save();

还有第三个但不推荐的选项，只需手动设置外键。

编辑：

$product->chapters()->associate($Chapters);
$product->save();

Laravel 5.1外键问题

1 个答案: