Laravel 9个不常常用的小技巧

1. 更新父表的timestamps

若是你想在更新关联表的同时，更新父表的timestamps，你只须要在关联表的model中添加touches属性。
好比咱们有Post和Comment两个关联模型

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Comment extends Model
{
    /**
     * 要更新的全部关联表
     *
     * @var array
     */
    protected $touches = ['post'];

    /**
     * Get the post that the comment belongs to.
     */
    public function post()
    {
        return $this->belongsTo('App\Post');
    }
}

2. 懒加载指定字段

$posts = App\Post::with('comment:id,name')->get();

3. 跳转指定控制器并附带参数

return redirect()->action('SomeController@method', ['param' => $value]);

4. 关联时使用withDefault()

在调用关联时，若是另外一个模型不存在，系统会抛出一个致命错误，例如 $comment->post->title，那么咱们就须要使用withDefault()

...
public function post()
{
    return $this->belongsTo(App\Post::class)->withDefault();
}

5. 两层循环中使用$loop

在blade的foreach中，若是你想获取外层循环的变量

@foreach ($users as $user)     
 @foreach ($user->posts as $post)         
    @if ($loop->parent->first)             
       This is first iteration of the parent loop.         
   @endif     
 @endforeach 
@endforeach

6. 浏览邮件而不发送

若是你使用的是mailables来发送邮件，你能够只展现而不发送邮件

Route::get('/mailable', function () {
    $invoice = App\Invoice::find(1);
    return new App\Mail\InvoicePaid($invoice);
});

7. 经过关联查询记录

在hasMany关联关系中，你能够查询出关联记录必须大于5的记录

$posts = Post::has('comment', '>', 5)->get();

8. 软删除

查看包含软删除的记录

$posts = Post::withTrashed()->get();

查看仅被软删除的记录

$posts = Post::onlyTrashed()->get();

恢复软删除的模型

Post::withTrashed()->restore();

9. Eloquent时间方法

$posts = Post::whereDate('created_at', '2018-01-31')->get(); 
$posts = Post::whereMonth('created_at', '12')->get(); 
$posts = Post::whereDay('created_at', '31')->get(); 
$posts = Post::whereYear('created_at', date('Y'))->get(); 
$posts = Post::whereTime('created_at', '=', '14:13:58')->get();