Question

数据库/迁移/2018_12_20_022430_create_products_table.php

> class CreateProductsTable extends Migration {
>     /**
>      * Run the migrations.
>      *
>      * @return void
>      */
>     public function up()
>     {
>         Schema::create('products', function (Blueprint $table) {
>             $table->increments('id');
>             $table->string ('name');
>             $table->text('description');
>             $table->decimal('price');
>             $table->string('file');
>             $table->timestamps();
>         });
>     }

数据库/迁移/2018_12_20_042857_create_cards_table.php

class CreateCardsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('cards', function (Blueprint $table) {
            $table->increments('id');
            $table->string ('quantity');
            $table->string('status');
            $table->integer('pid')->unsigned();
            $table->foreign('pid')->references('id')->on('products');
            $table->integer('cid')->unsigned();
            $table->foreign('cid')->references('id')->on('customers');

            $table->timestamps();
        });
    }

database / factories / UserFactory.php

$factory->define(App\Product::class, function (Faker $faker) { 
    return [
              //'id'=>$faker->numberBetween($min = 1, $max = 20),
              'name'=> $faker->word,
              'description'=> $faker->sentence($nbWords = 6, $variableNbWords = true),
              'price' => $faker->randomFloat($nbMaxDecimals = 100, $min = 1, $max = 10),
              'file' => $faker->imageUrl($width = 640, $height = 480),
    ];
});


$factory->define(App\Card::class, function (Faker $faker) {
    return [
               //'id'=>$faker->numberBetween($min = 1, $max = 20),
               'quantity'=>$faker->sentence($nbWords = 6, $variableNbWords = true),
               'status'=>$faker->boolean($chanceOfGettingTrue = 10),
               'cid'=>$faker->numberBetween($min = 1, $max = 20),
              'pid'=>$faker->numberBetween($min = 1, $max = 20),
    ];
});

routes / web.php

factory(App\Product::class,5)->create();
factory(App\Card::class,5)->create();

端子：

$ php artisan db:seed

错误：

在Connection.php第664行中：                                                                                     SQLSTATE [23000]：违反完整性约束：1452无法添加或   更新子行：外键约束失败   （{food。cards，约束ca rds_pid_foreign外键   （pid参考products（id））（SQL：插入cards中   （quantity，status，cid，pid，updated_at，creat ed_at）   值（Vitae asperiores eligendi ipsam exercitationem quidem。，1，
  18，8，2019-01-02 04:22:10，2019-01-02 04:22:10））

在Connection.php第458行中：                                                                                     SQLSTATE [23000]：违反完整性约束：1452无法添加或   更新子行：外键约束失败   （{food。cards，约束ca rds_pid_foreign外键   （{pid）参考文献products（id））

Answer 1

您必须使用产品和客户的ID代替随机数：

$factory->define(App\Card::class, function (Faker $faker) {
    $p_ids = App\Product::pluck('id')->toArray();
    $c_ids = App\Customer::pluck('id')->toArray();
    return [
               //'id'=>$faker->numberBetween($min = 1, $max = 20),
               'quantity'=>$faker->sentence($nbWords = 6, $variableNbWords = true),
               'status'=>$faker->boolean($chanceOfGettingTrue = 10),
               'cid'=>$faker->randomElement($c_ids),
               'pid'=> $faker->randomElement($p_ids),
    ];
});

简而言之，请从products和customers表中选择所有ID，并从它们中获取一个随机值以用作外键。

，但请确保您的工厂按特定顺序排列，因此必须在CardFactory和ProductFactory之后解雇CustomerFactory。

Answer 2

如果pid具有随机值，但是数据库不会在pid中不存在的cards table中输入products table的值。在pid中插入的值必须在product id中存在。

php artisan db：在为具有外键的表创建Faker时使用laravel错误进行种子植入

2 个答案: