如何在Laravel迁移中动态定义变形未赋值类型

php artisan make:migration modify_column_in_table --table=your_table_name

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

class ModifyColumnInTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::table('your_table_name', function (Blueprint $table) {
            $table->string('your_column_name')->nullable()->change();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::table('your_table_name', function (Blueprint $table) {
            $table->string('your_column_name')->change();
        });
    }
}

php artisan migrate