baoshi-was/database/migrations/2019_11_22_094213_create_units_table.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class CreateUnitsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('units', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->timestamps();
            $table->string('name',50)->unique()->comment('名称');
        });
        $units=['kg','m³','T'];
        for ($i=0;$i<count($units);$i++){
            \App\Unit::create([
                'name'=>$units[$i],
            ]);
        }
    }

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