安装最新laravel框架

composer create-project laravel/laravel --prefer-dist laravel9

　　换源

composer config -g repos.packagist composer https://mirrors.tencent.com/composer/

　　安装dcat-admin

composer require dcat/laravel-admin:"2.*" -vvv

　　然后运行下面的命令来发布资源：

php artisan admin:publish

　　运行如下命令完成安装：

php artisan admin:install

　　

use Illuminate\Support\Facades\Schema;
Schema::defaultStringLength(191);