migration: error 1215 Cannot add foreign key constraint

[ali_254]

hi ...

I made a table called: flights , Also, I want to create another table and run the "join" operation between them. this table called: flight_comments

 

table flights:

 public function up()
    {
        Schema::create('flights', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('name');
            $table->string('email')->unique();
            $table->timestamp('email_verified_at')->nullable();
            $table->string('password');
            $table->rememberToken();
            $table->timestamps();


        });

 

table flight_comments:

  public function up()
    {
        Schema::create('flight_comments', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->bigInteger('flight_id')->unsigned();
            $table->string('body','140');
            $table->nullabletimestamps();
            $table->foreign('flight_id')->references('id')->on('flights')->onDelete('cascade');
        });
    }

 

When I run the "migration" command, I get the following error:

 

In Connection.php line 647:

  SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint (SQL: alter table `flight_comments` add constraint `flight_
  comments_flight_id_foreign` foreign key (`flight_id`) references `flights` (`id`) on delete cascade)

In Connection.php line 449:

  SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint

 

 

please guide me

[Barand]

Is the column UNSIGNED in both tables?

[ali_254]

1 hour ago, Barand said:

Is the column UNSIGNED in both tables?

no , only in table flights

[Barand]

That was intended as a hint.

Make them both the same and you should then be able to create your foreign key.

[ali_254]

2 minutes ago, Barand said:

That was intended as a hint.

Make them both the same and you should then be able to create your foreign key.

thanks , but i delete all table in phpmyadmin and Reinstall the code "php artisan migrate" , Problem solved, thanks a lot