今天在使用一个第三方包 laravel-admin 时，出现了这样的错误：
SQLSTATE[42000]: Syntax error or access violation: 1103 Incorrect table name '',折腾了好久，终于知道了解决方法，原来是配置文件的缓存没有清理。

一、问题

vagrant@homestead:~/Code/laravel-shop$ php artisan admin:install

错误提示：

In Connection.php line 664:

  SQLSTATE[42000]: Syntax error or access violation: 1103 Incorrect table name '' (SQL: create table `` (`id` int uns
  igned not null auto_increment primary key, `username` varchar(190) not null, `password` varchar(60) not null, `name
  ` varchar(255) not null, `avatar` varchar(255) null, `remember_token` varchar(100) null, `created_at` timestamp nul
  l, `updated_at` timestamp null) default character set utf8mb4 collate utf8mb4_unicode_ci)


In Connection.php line 452:

  SQLSTATE[42000]: Syntax error or access violation: 1103 Incorrect table name ''

二、解决方案

database/migrations/2016_01_04_173148_create_admin_table.php

<?php

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

class CreateAdminTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        $connection = config('admin.database.connection') ?: config('database.default');

       // dd(app('config'));
        Schema::connection($connection)->create(config('admin.database.users_table'), function (Blueprint $table) {
            $table->increments('id');
            $table->string('username', 190)->unique();
            $table->string('password', 60);
            $table->string('name');
            $table->string('avatar')->nullable();
            $table->string('remember_token', 100)->nullable();
            $table->timestamps();
        });

        Schema::connection($connection)->create(config('admin.database.roles_table'), function (Blueprint $table) {
            $table->increments('id');
            $table->string('name', 50)->unique();
            $table->string('slug', 50);
            $table->timestamps();
        });

        Schema::connection($connection)->create(config('admin.database.permissions_table'), function (Blueprint $table) {
            $table->increments('id');
            $table->string('name', 50)->unique();
            $table->string('slug', 50);
            $table->string('http_method')->nullable();
            $table->text('http_path')->nullable();
            $table->timestamps();
        });

        Schema::connection($connection)->create(config('admin.database.menu_table'), function (Blueprint $table) {
            $table->increments('id');
            $table->integer('parent_id')->default(0);
            $table->integer('order')->default(0);
            $table->string('title', 50);
            $table->string('icon', 50);
            $table->string('uri', 50)->nullable();

            $table->timestamps();
        });

        Schema::connection($connection)->create(config('admin.database.role_users_table'), function (Blueprint $table) {
            $table->integer('role_id');
            $table->integer('user_id');
            $table->index(['role_id', 'user_id']);
            $table->timestamps();
        });

        Schema::connection($connection)->create(config('admin.database.role_permissions_table'), function (Blueprint $table) {
            $table->integer('role_id');
            $table->integer('permission_id');
            $table->index(['role_id', 'permission_id']);
            $table->timestamps();
        });

        Schema::connection($connection)->create(config('admin.database.user_permissions_table'), function (Blueprint $table) {
            $table->integer('user_id');
            $table->integer('permission_id');
            $table->index(['user_id', 'permission_id']);
            $table->timestamps();
        });

        Schema::connection($connection)->create(config('admin.database.role_menu_table'), function (Blueprint $table) {
            $table->integer('role_id');
            $table->integer('menu_id');
            $table->index(['role_id', 'menu_id']);
            $table->timestamps();
        });

        Schema::connection($connection)->create(config('admin.database.operation_log_table'), function (Blueprint $table) {
            $table->increments('id');
            $table->integer('user_id');
            $table->string('path');
            $table->string('method', 10);
            $table->string('ip', 15);
            $table->text('input');
            $table->index('user_id');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        $connection = config('admin.database.connection') ?: config('database.default');

        Schema::connection($connection)->dropIfExists(config('admin.database.users_table'));
        Schema::connection($connection)->dropIfExists(config('admin.database.roles_table'));
        Schema::connection($connection)->dropIfExists(config('admin.database.permissions_table'));
        Schema::connection($connection)->dropIfExists(config('admin.database.menu_table'));
        Schema::connection($connection)->dropIfExists(config('admin.database.user_permissions_table'));
        Schema::connection($connection)->dropIfExists(config('admin.database.role_users_table'));
        Schema::connection($connection)->dropIfExists(config('admin.database.role_permissions_table'));
        Schema::connection($connection)->dropIfExists(config('admin.database.role_menu_table'));
        Schema::connection($connection)->dropIfExists(config('admin.database.operation_log_table'));
    }
}

清除配置文件缓存

vagrant@homestead:~/Code/laravel-shop$ php artisan config:cache

再次执行发布命令，就可以了：

vagrant@homestead:~/Code/laravel-shop$ php artisan admin:install
Migrating: 2016_01_04_173148_create_admin_table
Migrated:  2016_01_04_173148_create_admin_table
Admin directory was created: /app/Admin
HomeController file was created: /app/Admin/Controllers/HomeController.php
ExampleController file was created: /app/Admin/Controllers/ExampleController.php
Bootstrap file was created: /app/Admin/bootstrap.php
Routes file was created: /app/Admin/routes.php
vagrant@homestead:~/Code/laravel-shop$