使用ID数组播种Laravel不起作用

I try to do seeding on a pivot table. Here is my code

public function run()
{
    // Get array of ids
    $teacherIds = DB::table('teachers')->pluck('id');
    $courseIds  = DB::table('courses')->pluck('id');

    // Seed course_teacher table
    foreach ((range(1, 1)) as $index)
    {
        DB::table('course_teacher')->insert(
            [
                'teacher_id' => $teacherIds[array_rand( (array) $teacherIds)],
                'course_id' => $courseIds[array_rand( (array) $courseIds)]
            ]
        );
    }
}

I added (array) because I had an error that I was giving an object while it wanted an array.

But since I have another error undefined index:

Can you help me ? Thank you very much

To make sure you get an array when getting $teacherIds and $courseIds, add the toArray function to make sure you are getting an array and not a Collection object.

// Get array of ids
$teacherIds = DB::table('teachers')->pluck('id')->toArray();
$courseIds  = DB::table('courses')->pluck('id')->toArray();

By doing this, you don't need to cast the array in the array_rand function either.

Update:

Even better would be to use the random function. This function will choose a random element for you.

$teacherIds = DB::table('teachers')->pluck('id');
$courseIds  = DB::table('courses')->pluck('id');

DB::table('course_teacher')->insert(
    [
        'teacher_id' => $teacherIds->random(),
        'course_id' => $courseIds->random()
    ]
);