laravel : seeder with foriegn keys - php

Question

in my database i have already tables namely: notifications table, statuses table, they have many to many relation, that is why i have a pivot table called notification_status. i created them with migrations and seed them with a seeder, all works fine. now i realize that i need one extra table which has many to one relation with notifications table(natification->hasMany->alertfrequency). when i tried to migrate it, it did allow me to do so.
here is my notification table
<?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');
}
}
and the alert frequency table, the new table i want to add,
<?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');
}
}
when i tried to add i get the following constrain
[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)
any one with a idea or suggestion. i appreciate all idea and suggestions.

Answer 1

From #AlexeyMezenin's answer, update based on Documentation:
Replace
$table->integer('notification_id')->unsigned();
with
$table->unsignedInteger('notification_id');

Answer 2

First thing you should do is to add unsigned(), because id is unsigned too:
$table->integer('notification_id')->unsigned();
If it'll not help, divide key creation and adding a foreign key constraint:
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

You need to migrate notifications table prior to alertFrequencies table as notification_id of alertFrequencies is referencing id of notifications table.
And you need to change $table->integer('notification_id'); to $table->integer('notification_id')->unsigned(); as you cannot accept minus ids as foreign key
And also make sure you have set your table engine set to InnoDB in your `config/database.php'.
$table->engine = 'InnoDB';