Question

在我的数据库中我已经有了表：通知表，状态表，它们有多对多的关系，这就是为什么我有一个名为notification_status的数据透视表。我用迁移创建它们并用播种机播种它们，一切正常。现在我意识到我需要一个额外的表，它与通知表有多对一的关系（natification-＆gt; hasMany-＆gt; alertfrequency）。当我试图迁移它时，它确实允许我这样做。这是我的通知表

<?php

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

class CreateNotificationsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('notifications', function (Blueprint $table) {
            $table->increments('id');
            $table->string('website_url');
            $table->string('email');
            $table->string('slack_channel');
            $table->string('check_frequency');
            $table->string('alert_frequency');
            $table->string('speed_frequency');
            $table->boolean('active');
            $table->timestamps();
        });
    }

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

和警报频率表，我要添加的新表，

 <?php

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

    class CreateAlertFrequenciesTable extends Migration
    {
        /**
         * Run the migrations.
         *
         * @return void
         */
        public function up()
        {
            Schema::create('alertFrequencies', function (Blueprint $table) {
                $table->increments('id');
                $table->integer('notification_id');
                $table->foreign('notification_id')
                      ->references('id')->on('notifications')
                      ->onDelete('cascade');
                $table->timestamps();
            });
        }

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

当我试图添加时，我得到以下约束

  [Illuminate\Database\QueryException]
  SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint (SQL: alter table `alertFrequencies` add constraint `alertfrequencies_notification_id_foreign` foreign key (`notification_
  id`) references `notifications` (`id`) on delete cascade)

任何有想法或建议的人。我很感激所有的想法和建议。

Answer 1

来自@ AlexeyMezenin的答案，根据Documentation进行更新：取代

y <- cbind(x,z)
colnames(y) <- make.names(colnames(y), unique = TRUE)

带

$table->integer('notification_id')->unsigned();

Answer 2

首先应该添加unsigned()，因为id也是无符号的：

$table->integer('notification_id')->unsigned();

如果它没有帮助，则划分密钥创建并添加外键约束：

Schema::create('alertFrequencies', function (Blueprint $table) {
    $table->increments('id');
    $table->integer('notification_id')->unsigned();
    $table->timestamps();
});

Schema::table('alertFrequencies', function (Blueprint $table) {
    $table->foreign('notification_id')->references('id')->on('notifications')->onDelete('cascade');
});

Answer 3

您需要在notifications表之前迁移alertFrequencies表，notification_id的{{1}}引用alertFrequencies表的id。

您需要将notifications更改为$table->integer('notification_id');，因为您无法接受$table->integer('notification_id')->unsigned(); ID minus

并确保在`config / database.php＆＃39;中将表引擎设置为foreign key。

InnoDB

laravel：带有外键的播种机

3 个答案: