模型关联增加条件
来源：7-3 介绍Laravel模型关联
AMOR跳跳
2018-11-27
老师，有这么一个需求：
获取所有栏目下面的信息，这些信息需要按照修改时间排序，然后limit 4，请问如何获取。
目前的代码：
Category 模型：
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
use Encore\Admin\Traits\AdminBuilder;
use Encore\Admin\Traits\ModelTree;
class Category extends Model
{
use ModelTree, AdminBuilder;
protected $table = 'admin_categories';
public function info() {
return $this->hasMany(Info::class, 'category_id');
}
}
Info 模型：
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
class Info extends Model
{
protected $table = 'admin_infos';
public function category() {
return $this->belongsTo(Category::class, 'category_id');
}
}
这个问题其实和教程中，我想获取所有文章下的评论，每个文章4条评论，每个评论按照修改时间获取。一样一样的，通过关联模型如何获取呢？
写回答
1回答
-
AMOR跳跳
提问者
2018-11-27
# 关于这个问题，我有个一个解答 （不知道是否还有更好的方法） # 这是路由： Route::get('category/infos', function(\App\Models\Category $category, \App\Models\Info $info){ return $category::all()->each(function($item, $key) { $item->apiInfo->toArray(); }); }); # 这个Category 模型 <?php namespace App\Models; use Illuminate\Database\Eloquent\Model; use Encore\Admin\Traits\AdminBuilder; use Encore\Admin\Traits\ModelTree; class Category extends Model { use ModelTree, AdminBuilder; protected $table = 'admin_categories'; public function apiInfo(string $where = null, int $is_limit = null) { return $this->hasMany(Info::class, 'category_id')->limit(4)->orderByDesc('updated_at'); // return $this->hasMany(Info::class, 'category_id'); } // 用作数据填充的关联关系方法 public function info_f() { return $this -> hasMany(Info::class, 'category_id'); } } # 这是返回的JSON [ { "id":1, "parent_id":0, "order":0, "title":"pcsoft", "classpath":"pcsoft", "created_at":"2018-11-27 14:36:32", "updated_at":"2018-11-27 14:36:32", "api_info":Array[4] }, { "id":2, "parent_id":1, "order":0, "title":"work", "classpath":"work", "created_at":"2018-11-27 14:47:54", "updated_at":"2018-11-27 14:47:54", "api_info":Array[4] }, { "id":3, "parent_id":0, "order":0, "title":"pcgame", "classpath":"pcgame", "created_at":"2018-11-27 14:48:05", "updated_at":"2018-11-27 14:48:05", "api_info":Array[4] }, { "id":4, "parent_id":0, "order":0, "title":"iossoft", "classpath":"iossoft", "created_at":"2018-11-27 14:48:22", "updated_at":"2018-11-27 14:48:22", "api_info":Array[4] }, { "id":5, "parent_id":0, "order":0, "title":"iosgame", "classpath":"iosgame", "created_at":"2018-11-27 14:48:32", "updated_at":"2018-11-27 14:48:32", "api_info":Array[4] }, { "id":6, "parent_id":3, "order":0, "title":"selfpc", "classpath":"selfpc", "created_at":"2018-11-27 14:48:52", "updated_at":"2018-11-27 14:48:52", "api_info":[ { "id":128, "title":"Ms.", "info_url":"http://pfeffer.com/", "image_url":"https://lorempixel.com/640/480/?35123", "category_id":6, "created_at":"2005-06-26 14:23:56", "updated_at":"2016-06-27 22:56:55" }, { "id":163, "title":"Prof.", "info_url":"http://www.herzog.info/", "image_url":"https://lorempixel.com/640/480/?88262", "category_id":6, "created_at":"2010-07-15 00:04:26", "updated_at":"2015-03-15 01:15:52" }, { "id":198, "title":"Prof.", "info_url":"http://kohler.com/ad-autem-laboriosam-quo.html", "image_url":"https://lorempixel.com/640/480/?93485", "category_id":6, "created_at":"1980-08-23 08:08:37", "updated_at":"2013-07-19 14:34:24" }, { "id":18, "title":"Prof.", "info_url":"https://reilly.com/fuga-consequatur-sit-sequi-quae-odio-distinctio-numquam.html", "image_url":"https://lorempixel.com/640/480/?94247", "category_id":6, "created_at":"2011-02-02 01:48:33", "updated_at":"2013-03-12 09:51:44" } ] }, { "id":7, "parent_id":4, "order":0, "title":"wechat", "classpath":"wecaht", "created_at":"2018-11-27 14:49:09", "updated_at":"2018-11-27 14:49:09", "api_info":[ { "id":103, "title":"Mrs.", "info_url":"http://www.ward.org/", "image_url":"https://lorempixel.com/640/480/?41503", "category_id":7, "created_at":"2002-05-08 09:40:09", "updated_at":"2015-05-29 22:29:09" }, { "id":173, "title":"Prof.", "info_url":"http://nicolas.com/ea-labore-non-animi-aut-totam-dicta-reprehenderit", "image_url":"https://lorempixel.com/640/480/?99170", "category_id":7, "created_at":"1983-12-06 13:09:28", "updated_at":"2014-03-24 04:23:00" }, { "id":42, "title":"Dr.", "info_url":"http://www.hirthe.info/", "image_url":"https://lorempixel.com/640/480/?50939", "category_id":7, "created_at":"1999-05-21 08:20:05", "updated_at":"2014-02-15 16:39:58" }, { "id":120, "title":"Mr.", "info_url":"http://www.schinner.com/at-occaecati-eveniet-aut-ut-aspernatur-ratione", "image_url":"https://lorempixel.com/640/480/?79172", "category_id":7, "created_at":"1985-04-27 16:17:02", "updated_at":"2013-05-22 17:06:40" } ] } ]00