tielu/database/seeds/TemplateCategorySeeder.php

<?php

use Illuminate\Database\Seeder;

class TemplateCategorySeeder extends Seeder
{
    /**
     * Run the database seeds.
     *
     * @return void
     */
    public function run()
    {
        $list = \App\Models\TemplateInfoModel::all();
        foreach ($list as $item) {
            \App\Models\TemplateCategoryRelation::firstOrCreate([
                'template_id' => $item->id,
                'category_id' => $item->class_id
            ]);
        }
    }
}