无法迁移外键

Question

UPDATE: I'm going to abandon the foreign key stuff for now. Seems like my project is broken on a fundamental level so I'll revisit this project sometime later. I appreciate the two helpful lads in the comments.

I'm trying to encorporate foreign keys into my Laravel application but I just keep getting stuck. I keep getting "errno: 150 "Foreign key constaint is incorrectly formed".

Even after trying multiple solutions, deleting the table, changing migration order etc, I keep getting back to this error. It's extremely frustrating.

I have also tried php artisan migrate:refresh and php artisan migrate:reset but nothing seems to help.

In the code below there is a piece of code from the CreateQuestionsTable class

        Schema::table('questions', function(Blueprint $table){
        $table->foreign('answerTypeName')->references('answerType')->on('answerstypes');
    });

I have tried to put this in the CreateAnswersTable class but that didn't solve it either.

In the code below there is another piece of code from the CreateQuestionsTable class

        Schema::create('questions', function (Blueprint $table) {
        $table->increments('id');
        $table->string('questionName');
        $table->string('answerTypeName');
        $table->timestamps();
    });

Here I also tried to change answerTypeName to answerTypeId with $table->integer but that also didn't help.

class CreateQuestionsTable extends Migration
{
 /**
 * Run the migrations.
 *
 * @return void
 */
public function up()
{
    Schema::create('questions', function (Blueprint $table) {
        $table->increments('id');
        $table->string('questionName');
        $table->string('answerTypeName');
        $table->timestamps();
    });

    Schema::table('questions', function(Blueprint $table){
        $table->foreign('answerTypeName')->references('answerType')->on('answerstypes');
    });
}
}

class CreateAnswertypesTable extends Migration
{
/**
 * Run the migrations.
 *
 * @return void
 */
public function up()
{
    Schema::create('answerstypes', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('answerType');
        $table->timestamps();
    });


}
}

This is an error that keeps popping up

PDOException::("SQLSTATE[HY000]: General error: 1005 Can't create table `impact_dockwize`.`questions` (errno: 150 "Foreign key constraint is incorrectly formed")")

I expect it to work like this but the error keeps popping up when I try to do php artisan migrate. As I mentioned above, applying php artisan migrate:refresh or reset doesn't seem to work as well.

Answer 1

Look at this:

Schema::table('questions', function(Blueprint $table){
    $table->foreign('answerTypeName')->references('answerType')->on('answerstypes');
});

Remove it and leave it like this:

Schema::create('questions', function (Blueprint $table) {
    $table->increments('id');
    $table->string('questionName');
    $table->string('answerTypeName');
    $table->timestamps();

    $table->foreign('answerTypeName')->references('answerType')->on('answerstypes');
});

Hope it helps!