How to create a self-reference relationship (foreign key) in a Laravel migration?

Question

I am starting with a self-learning project built on top of Laravel 5.2 and I have found my first issue: self-reference in a migration.

This is how the file 2016_08_02_024942_create_navigation_table.php looks like (I have remove the comments for not make the post too long):

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

class CreateNavigationTable extends Migration
{
    public function up()
    {
        Schema::create('navigation', function (Blueprint $table) {
            $table->engine = 'InnoDB';
            $table->increments('id')->unsigned();
            $table->integer('position')->unsigned();
            $table->string('title');
            $table->string('slug');
            $table->string('permissions')->nullable();
            $table->timestamps();
            $table->softDeletes();
        });
    }

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

And then because I have read several posts here like this, this, this and many more I make another file with just the relation named as 2016_08_02_030158_add_parent_to_navigation_table.php with the following code:

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

class AddParentToNavigationTable extends Migration
{
    public function up()
    {
        Schema::table('navigation', function (Blueprint $table) {
            $table->foreign('parent_id')->references('id')->on('navigation')->onUpdate('cascade')->onDelete('cascade');
        });
    }

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

But when I run the command php artisan migrate I got the following error and I am not sure what I am doing wrong:

[Illuminate\Database\QueryException] SQLSTATE[42S01]: Base table or view already exists: 1050 Table 'navigation' already exists (SQL: create table navigation (id int unsigned not null auto_increment primary key, position int unsigned not null, title varc har(255) not null, slug varchar(255) not null, permissions varchar(255) null, created_at timestamp null, updated_at timestamp null, deleted_at timestamp null) default character set utf8 collate utf8_unicode_ci engin e = InnoDB)

[PDOException] SQLSTATE[42S01]: Base table or view already exists: 1050 Table 'navigation' already exists

Can any give me some advice? What I am doing wrong? I have see this package but I am not sure if it will solve my issue.

Answer 1

SQLSTATE[42S01]: Base table or view already exists: 1050 Table 'navigation' already exists

Means you have same table name in database

So you need to verify, you don't have any table with that name in the database.

• Make sure no table name with the same name

• Run migration again

  php artisan migration:rollback Sometimes fails to drop table for different reasons.