1071 Specified key was too long; max key length is 1000 bytes

laravel用php artisan migrate在 mysql中创建表时候报错：1071 Specified key was too long; max key length is 1000 bytes

原因：索引的长度超过mysql的限定长度1000 bytes

解决方法：在提供者AppServiceProvider 中调用 Schema::defaultStringLength 方法来完成配置

use Illuminate\Support\Facades\Schema;

/**
 * Bootstrap any application services.
 *
 * @return void
 * @translator laravelacademy.org
 */
public function boot()
{
    Schema::defaultStringLength(191);
}