How sol solve this database migration issue? - database

Question

I'm having trouble with Laravel database migration. I have entered foreign key constraint in my database migration file, but when I try to migrate the file it shows this error message.
Illuminate\Database\QueryException : SQLSTATE[42000]: 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 the right syntax to use near ') on delete cascade on update cascade' at line 1 (SQL: alter table education_qualifications add constraint education_qualifications_teacher_id_foreign foreign key (teacher_id) references teachers () on delete cascade on update cascade)at E:\XAMPP\htdocs\ViduresaApp\vendor\laravel\framework\src\Illuminate\Database\Connection.php:664
660| // If an exception occurs when attempting to run a query, we'll format the error
661| // message to include the bindings with SQL, which will make this exception a
662| // lot more helpful to the developer instead of just the database's errors.
663| catch (Exception $e) {
> 664| throw new QueryException(
665| $query, $this->prepareBindings($bindings), $e
666| );
667| }
668|
Exception trace:
1 PDOException::("SQLSTATE[42000]: 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 the right syntax to use near ') on delete cascade on update cascade' at line 1")
E:\XAMPP\htdocs\ViduresaApp\vendor\laravel\framework\src\Illuminate\Database\Connection.php:452
2 PDO::prepare("alter table education_qualifications add constraint education_qualifications_teacher_id_foreign foreign key (teacher_id) references teachers () on delete cascade on update cascade")
E:\XAMPP\htdocs\ViduresaApp\vendor\laravel\framework\src\Illuminate\Database\Connection.php:452
<?php
use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;
class CreateEducationQualificationsTable extends Migration
{
/**
* Run the migrations.
*
* #return void
*/
public function up()
{
Schema::create('education_qualifications', function (Blueprint $table) {
$table->increments('id');
$table->unsignedInteger('teacher_id')->nullable();
$table->unsignedInteger('student_id')->nullable();
$table->string('institute_name');
$table->string('user_degree');
$table->string('field_of_study');
$table->string('user_grade');
$table->date('from_date')->nullable();
$table->date('to_date')->nullable();
$table->text('edu_description');
$table->timestamps();
$table->foreign('teacher_id')->references('id')->on('teachers')->onUpdate('cascade')->onDelete('cascade');
$table->foreign('student_id')->references('id')->on('users')->onUpdate('cascade')->onDelete('cascade');
$table->primary(['teacher_id', 'student_id']);
});
}
/**
* Reverse the migrations.
*
* #return void
*/
public function down()
{
Schema::dropIfExists('education_qualifications');
}
}

Answer 1

You can use both onupdate and ondelete at the same line
For example:
$table->foreign(’author’)->references(’id’)->on(’users’)->onUpdate(’cascade’);