SQLSTATE[HY000]：一般错误：无法创建表

Question

I am using Laravel 8.21.0 on a CentOS 8 server. I am using mariaDB. I have 3 tables: tests, students and grades. I am trying to set foreign key of tests and students on the grades table. However, when I run my migrations, I get errorno 150: Foreign key constraint is incorrectly formed.

Here are my migrations:

Grades table:

class CreateGradesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('grades', function (Blueprint $table) {
            
           $table->id('id')->unique();
           $table->unsignedInteger('student_id');
           $table->string('test_id');

           $table->foreign('test_id')->references('id')->on('tests');
           $table->foreign('student_id')->references('id')->on('students');

           $table->date('testDate');
           $table->integer('testCount');
           $table->integer('vocabScore');
           $table->integer('readingScore');
           $table->integer('listeningScore');
           $table->integer('rawTotal');
           $table->integer('adjustVocabScore');
           $table->integer('adjustReadingScore');
           $table->integer('adjustlisteningScore');
           $table->integer('adjustTotal');
           $table->string('passOrfail');
           $table->timestamps();
            
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('grades');
    }
}

Student Table migrations:

class CreateStudentsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('students', function (Blueprint $table) {
          
            $table->integer('id')->unique();
            $table->string('name');
            $table->date('DOE');
            $table->string('belongsTo');
            $table->string('country');
            $table->string('level');
            $table->string('year');
            $table->timestamps();
            
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('students');
    }
}

Test table:

class CreateTestsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('tests', function (Blueprint $table) {
         
            $table->string('id')->unique();
            $table->string('testName');
            $table->string('level');
            $table->integer('vocabFullScore');
            $table->integer('readingFullScore');
            $table->integer('listeningFullScore');
            $table->integer('totalFullScore');
            $table->integer('vocabPassScore');
            $table->integer('readingPassScore');
            $table->integer('listeningPassScore');
            $table->integer('totalPassScore');
            $table->timestamps();
            
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('tests');
    }
}

The bizzare thing is that the migrations table gets created successfully when I run it on localhost WAMP server but it throws me an error on CENTOS server. Does anyone have any idea on how to solve this?

Things that I have tried doing but did not work:

・Changed database to InnoDB  by specifying 'engine' => 'InnoDB' on each model.
・Made sure that the order of migration is correct. First migrated student table, then tests and lastly grades.
・Ensure that the data type of the foreign key is correct on grades table. 

Any ideas would be greatly appreciated. :'(

Edit: I set the foreign key type of student_id as integer. In grades table migration:

$table->integer('student_id');
$table->foreign('student_id')->references('id')->on('students');

In students table migration:

$table->integer('id')->unique();

After doing this I am getting a new error:

Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for right syntax to use near ')' at line 1 (SQL: alter table 'grades' add constraint 'grades_test_id_foreign' foreign key ('test_id') references 'tests' ()) 

at vendor/laravel/framework/src/Illuminate/Database/Connection.php:678
catch(Exception $e){
 throw new QueryException(
  $query, $this->prepareBindings($bindings),$e
);
}
+9 vendor frames
database/migrations/2021_01_13_064711_create_grades_table.php:54
Illuminate\Support\Facades\Facade::__callStatic()

+32 vendor frames
artisan:37
Illuminate\Foundation\Console\Kernel::handle()

Answer 1

Change

$table->unsignedInteger('student_id');

to

$table->integer('student_id');

in grades table to match the datatypes to form a constraint.