Foreign key add constraint error in laravel migration - mysql

Question

I have written the migration in laravel but when I run this migration I received following error
> SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint
> (SQL: alter table `campaign_notifications` add constraint `campaign
> _notifications_campaign_id_foreign` foreign key (`campaign_id`) references `campaigns` (`id`) on delete cascade)
My migration code
Schema::create('campaign_notifications', function (Blueprint $table) {
$table->increments('id');
$table->integer('campaign_id')->index();
$table->string('user_uuid')->nullable();
$table->string('post_id')->default(0);
$table->tinyInteger('is_opened')->default(0);
$table->tinyInteger('sent')->default(0);
$table->string('payload')->nullable();
$table->string('failed_type')->nullable();
$table->timestamps();
$table->foreign('campaign_id')->references('id')->on('campaigns')->onDelete('cascade');
});

Answer 1

First make sure you already have a campaign table in your DB (Take a look in the timestamps of your migrations), so that you can reference the table in your current migration. Basically for this migration to work you need a campaign table in your database, you can't run the campaign table migration after this one.
Also, change your campaign_id to unsigned integer
$table->unsignedInteger('campaign_id');
$table->foreign('campaign_id')->references('id')->on('campaigns')->onDelete('cascade');

Answer 2

Your migration code will look like :
Schema::create('campaign_notifications', function (Blueprint $table) {
$table->increments('id');
$table->string('user_uuid')->nullable();
$table->string('post_id')->default(0);
$table->tinyInteger('is_opened')->default(0);
$table->tinyInteger('sent')->default(0);
$table->string('payload')->nullable();
$table->string('failed_type')->nullable();
$table->bigInteger('campaign_id')->unsigned();
$table->foreign('campaign_id')->references('id')->on('campaigns')->onDelete('cascade');
$table->index('campaign_id');
$table->timestamps();
});