Laravel 5.4+ 设置数据库返回格式为数组 setFetchMode(\PDO::FETCH_ASSOC)

查看官方文档：https://laravel.com/docs/5.4/upgrade

Fetch Mode
Laravel no longer includes the ability to customize the PDO "fetch mode" from your configuration files. Instead, PDO::FETCH_OBJ is always used. If you would still like to customize the fetch mode for your application you may listen for the new  Illuminate\Database\Events\StatementPrepared event:

Event::listen(StatementPrepared::class, function ($event) {
    $event->statement->setFetchMode(...);
});

从5.4开始， 不能再通过配置文件的方式去改变fetch mode了。而使用了事件监听设置去实现该配置。

打开app/Providers/EventServiceProvier.php， 按照官方文档，先引入Illuminate\Database\Events\StatementPrepared类，然后在boot方法中加入上方样例代码，最终代码如下：

<?php
namespace App\Providers;

use Illuminate\Support\Facades\Event;
use Illuminate\Foundation\Support\Providers\EventServiceProvider as ServiceProvider;
use Illuminate\Database\Events\StatementPrepared;

class EventServiceProvider extends ServiceProvider
{
    /**
     * The event listener mappings for the application.
     *
     * @var array
     */
    protected $listen = [
        'App\Events\Event' => [
            'App\Listeners\EventListener',
        ],
    ];

    /**
     * Register any events for your application.
     *
     * @return void
     */
    public function boot()
    {
        parent::boot();

        //
        Event::listen(StatementPrepared::class, function ($event) {
            $event->statement->setFetchMode(\PDO::FETCH_ASSOC);
        });
    }
}

我们设置了以关联数组的方式返回该查询结果即fetch mode设置为FETCH_ASSOC，注意，该设置只对Query Builder有效。